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Tamil Nadu · TNEB · bi-monthly slab logic

TNEB Bill Calculator 2026 — Tamil Nadu Electricity Bill with 200 Free Units

Estimate your Tamil Nadu electricity bill

This TNEB bill calculator works out a Tamil Nadu domestic bill on the tariff TNPDCL bills today. TNEB bills homes bi-monthly: the first 200 units are free when the two-month total is 500 units or less, and only the first 100 are free above that. Enter your units or meter readings for a slab-by-slab bill, an old-versus-new comparison and a monthly equivalent.

Worked example

A 300-unit bi-monthly bill works out to

₹012345678901234567890123456789
Energy
₹470.00

₹11.55

Top slab rate

bi-monthly

Billing

None

FCA / unit

100–200u

Free subsidy

Calculate your bill

Electricity Bill Calculator

Accurate estimates for Tamil Nadu · TNEB

Connection type
kWh
Billing periodbi-monthly

Results are approximate estimates. Your actual bill may vary.

Estimated bi-monthly bill

₹470.00

≈ ₹235.00 / month (150 units)

1–400 @ ₹4.7 × 300₹1,410.00
Energy charge₹1,410.00
100 free units (all domestic consumers) + Second 100 free units (bi-monthly use up to 500 units)−₹940.00
Total₹470.00

You are 200 units below 500. At 501 units the bill becomes ₹2,048.00, which is ₹478.00 more than the ₹1,570.00 charged at 500 units, because fewer units are free above that level.

Old vs new: before 10 May 2026 the same 300 units cost ₹940.00. You pay ₹470.00 less now.

Worked example

A 300-unit bi-monthly Tamil Nadu residential bill (single-phase) works out to ₹012345678901234567890123456789 — about ₹235.00 per month. That is ₹1,410.00 energy − ₹940.00 subsidy.

See the full breakdown ↓

Have a fixed budget? Work backwards

Enter what you want to spend, and we'll tell you the maximum units that stays within it — the exact inverse of the calculator above.

Budget → Units Calculator

Tell us your target bill, we'll tell you how many units that buys

Connection type

You can use up to

409 units

for a bi-monthly bill of ₹997.00 (within your ₹1,000.00 budget)

How to use this calculator

  1. 1Select your state — it's pre-selected for this page
  2. 2Enter the units consumed shown on your bill, or your meter readings
  3. 3Choose your connection phase (single or three) if applicable
  4. 4Review the itemised slab-by-slab result below the calculator

The bi-monthly rule

TNEB bills bi-monthly. The units you enter represent your full ~60-day billing period — not a single month. To compare against a monthly figure, we divide the total by 2, shown as the monthly-equivalent on your result.

The 500-unit line

500 units

₹1,570

501 units

₹2,048

Up to 500 units in a bi-monthly cycle, the first 200 units are free. At 501 units only the first 100 are free, so one extra unit raises the bill by ₹478. Both figures are from TNPDCL’s own bill calculator.

What are slabs in electricity billing?

Most Indian DISCOMs bill domestic electricity using telescopic slabs — tiered per-unit rates that rise as your consumption increases.

  • Each slab has its own rate — for example the first 100 units might be billed at one rate and the next 100 at a higher one.
  • Slabs are telescopic, not retroactive — only the units that fall inside a higher slab are billed at that slab's rate, not your entire consumption.
  • The slab count resets every billing cycle — monthly, bimonthly or quarterly, depending on your DISCOM.
  • Some DISCOMs add a fuel cost adjustment or electricity duty on top of the slab rate — see the tariff table above for what applies here.

Read a full worked example of how telescopic slabs work →

Estimate not matching your real bill? See why fixed charges, FCA and duty sit on top of this estimate →

Tamil Nadu residential tariff slabs

Slab (units)Rate (₹/unit)
0–400₹4.70
401–500₹6.30
501–600₹8.40
601–800₹9.45
801–1000₹10.50
1001–above₹11.55
Fixed chargeNone

Effective from 10 May 2026 · Verified 10 October 2026 · source order

View Commercial, Industrial & Agriculture tariffs for Tamil Nadu →

Two worked examples

Lower usage

₹470.00

300 units · ₹1,410.00 energy − ₹940.00 subsidy

Higher usage

₹4,014.00

720 units · ₹4,484.00 energy − ₹470.00 subsidy

Explore estimated electricity bills for commonly used consumption levels using TNEB tariff slabs for Domestic connections in Tamil Nadu.

Electricity Bill for 50 Units in Tamil Nadu₹0.00

The estimated electricity bill for 50 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹0.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–40050₹4.70₹235.00

Detailed Charges Breakdown

Energy Charges
₹235.00
Subsidy
−₹235.00
Fixed Charges
₹0.00
Total Bill Amount₹0.00
Electricity Bill for 100 Units in Tamil Nadu₹0.00

The estimated electricity bill for 100 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹0.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400100₹4.70₹470.00

Detailed Charges Breakdown

Energy Charges
₹470.00
Subsidy
−₹470.00
Fixed Charges
₹0.00
Total Bill Amount₹0.00
Electricity Bill for 150 Units in Tamil Nadu₹0.00

The estimated electricity bill for 150 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹0.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400150₹4.70₹705.00

Detailed Charges Breakdown

Energy Charges
₹705.00
Subsidy
−₹705.00
Fixed Charges
₹0.00
Total Bill Amount₹0.00
Electricity Bill for 200 Units in Tamil Nadu₹0.00

The estimated electricity bill for 200 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹0.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400200₹4.70₹940.00

Detailed Charges Breakdown

Energy Charges
₹940.00
Subsidy
−₹940.00
Fixed Charges
₹0.00
Total Bill Amount₹0.00
Electricity Bill for 250 Units in Tamil Nadu₹235.00

The estimated electricity bill for 250 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹235.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400250₹4.70₹1,175.00

Detailed Charges Breakdown

Energy Charges
₹1,175.00
Subsidy
−₹940.00
Fixed Charges
₹0.00
Total Bill Amount₹235.00
Electricity Bill for 300 Units in Tamil Nadu₹470.00

The estimated electricity bill for 300 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹470.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400300₹4.70₹1,410.00

Detailed Charges Breakdown

Energy Charges
₹1,410.00
Subsidy
−₹940.00
Fixed Charges
₹0.00
Total Bill Amount₹470.00
Electricity Bill for 400 Units in Tamil Nadu₹940.00

The estimated electricity bill for 400 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹940.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400400₹4.70₹1,880.00

Detailed Charges Breakdown

Energy Charges
₹1,880.00
Subsidy
−₹940.00
Fixed Charges
₹0.00
Total Bill Amount₹940.00
Electricity Bill for 500 Units in Tamil Nadu₹1,570.00

The estimated electricity bill for 500 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹1,570.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400400₹4.70₹1,880.00
400–500100₹6.30₹630.00

Detailed Charges Breakdown

Energy Charges
₹2,510.00
Subsidy
−₹940.00
Fixed Charges
₹0.00
Total Bill Amount₹1,570.00
Electricity Bill for 750 Units in Tamil Nadu₹4,298.00

The estimated electricity bill for 750 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹4,298.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400400₹4.70₹1,880.00
400–500100₹6.30₹630.00
500–600100₹8.40₹840.00
600–800150₹9.45₹1,417.50

Detailed Charges Breakdown

Energy Charges
₹4,767.50
Subsidy
−₹470.00
Fixed Charges
₹0.00
Total Bill Amount₹4,298.00
Electricity Bill for 1000 Units in Tamil Nadu₹6,870.00

The estimated electricity bill for 1000 units under Tamil Nadu Power Distribution Corporation Ltd (TNPDCL, formerly TANGEDCO) in Tamil Nadu is ₹6,870.00. This estimate is based on the latest tariff rates for Domestic connections. Your actual bill may vary depending on applicable fuel surcharge, electricity duty, fixed charges, taxes and other billing rules.

Slab-wise Energy Charges

Slab RangeUnitsRate/UnitAmount
0–400400₹4.70₹1,880.00
400–500100₹6.30₹630.00
500–600100₹8.40₹840.00
600–800200₹9.45₹1,890.00
800–1000200₹10.50₹2,100.00

Detailed Charges Breakdown

Energy Charges
₹7,340.00
Subsidy
−₹470.00
Fixed Charges
₹0.00
Total Bill Amount₹6,870.00

Common TNEB bill traps

The 500-unit cliff

The second 100 free units are given only when the bi-monthly total is 500 units or less. At 501 units they are withdrawn for the whole bill, so the total jumps from ₹1,570 to ₹2,048. A household near 500 units gains the most from watching the meter in the last week of a cycle.

“200 free units” does not apply to everyone

A bill above 500 units still gets the first 100 units free, as before 10 May 2026, but not the second 100. A 600-unit bill is ₹2,880 under both the old and the new rules.

Rate tables that show ₹4.95

Some tables list ₹4.95 as the first paid rate. That is the tariff before the Government subsidy, which TNPDCL's calculator shows as “Total Current Charges”. The amount a domestic consumer pays works out to ₹4.70 for that slab, and ₹6.30, ₹8.40, ₹9.45, ₹10.50 and ₹11.55 for the slabs above it.

Reading-date drift

Because billing is bi-monthly, your meter-read date can drift by a few days each cycle. Comparing “this January's bill” to “last January's bill” isn't always a clean 60-day-to-60-day comparison — check the actual reading dates on both bills before concluding your usage changed.

How the TNEB bill is calculated

Bi-monthly cycle

TNPDCL reads domestic meters once every two months, so a TNEB bill covers roughly 60 days. Every slab limit and the free-unit allowance apply to that two-month total, which is the main source of confusion when comparing with a monthly bill.

Free units: 200 or 100

Every domestic consumer gets the first 100 units of a cycle free. From 10 May 2026, units 101–200 are free as well, but only when the bi-monthly total is 500 units or less. Above 500 units, only the first 100 are free.

Slab rates after the free units

Paid units are billed slab by slab: ₹4.70 up to 400 units, ₹6.30 for 401–500, ₹8.40 for 501–600, ₹9.45 for 601–800, ₹10.50 for 801–1,000 and ₹11.55 above 1,000. TNPDCL's own calculator shows no fixed charge or electricity tax on a domestic bill, and rounds the result to a whole rupee.

Your bill, component by component

Based on the 300-unit example above. Expand each line for what it means and whether you can influence it.

Energy chargeReducible₹1,410.00+

Priced across telescopic slabs — the more you use, the higher the marginal rate. Shifting usage below your next slab threshold lowers this line directly. This example totals ₹1,410.00.

SubsidyWorth checking₹940.00+

100 free units (all domestic consumers), Second 100 free units (bi-monthly use up to 500 units) reduced this bill by ₹940.00. This is the one line worth double-checking against your paper bill — confirm your eligibility status is correctly marked.

What's included in your bill

ComponentWhat it isTypical range
Energy chargeUnits × slab rate, telescopic₹4.70–₹11.55/unit
Fixed chargeFlat, independent of usageNone
Subsidy100 free units (all domestic consumers)100 free units
SubsidySecond 100 free units (bi-monthly use up to 500 units)100 free units

How to read your meter

Digital meters show a running total in kWh ("units") on an LCD display — write down the number before the decimal point. To find your consumption for a billing period, subtract your previous reading from your current reading; that is exactly what the "Meter reading" mode in the calculator above does for you. Analog meters use a set of dial gauges read left to right — note the number the pointer has just passed on each dial.

Tools that cut your bill

Swap CFL for LED bulbs

Replacing a 15W CFL with a 9W LED bulb, run 6 hrs/day, saves about ₹151.77/year at Tamil Nadu's top slab rate (₹11.55/unit) — per bulb.

How does TNEB compare?

Your DISCOM
TN

TNEB

Tamil Nadu

Top slab rate

₹11.55/unit

Base slab

₹4.70

Slabs

6

Billing

bi-monthly

Duty

0%

Most ExpensiveView Full Calculator →
KS

KSEB

Kerala

Top slab rate

₹8.50/unit

↓ 26% cheaper than TNEB

Base slab

₹3.35

Slabs

6

Billing

bi-monthly

Duty

5%

Cheapest HereKSEB Calculator →
BE

BESCOM

Karnataka

Top slab rate

₹8.60/unit

↓ 26% cheaper than TNEB

Base slab

₹5.90

Slabs

3

Billing

monthly

Duty

0%

ModerateBESCOM Calculator →
AP

APSPDCL

Andhra Pradesh

Top slab rate

₹9.75/unit

↓ 16% cheaper than TNEB

Base slab

₹1.90

Slabs

6

Billing

monthly

Duty

0%

ModerateAPSPDCL Calculator →

Top Slab Rate Comparison

KSEB
₹8.50
Kerala
BESCOM
₹8.60
Karnataka
APSPDCL
₹9.75
Andhra Pradesh
TNEB
₹11.55
Tamil Nadu

TNEB's top domestic slab rate is ₹11.55/unit — cheaper than KSEB (₹8.50/unit), — cheaper than BESCOM (₹8.60/unit), — cheaper than APSPDCL (₹9.75/unit). Billing cycles also differ: TNEB bills bi-monthly, while KSEB bills bi-monthly, BESCOM bills monthly, APSPDCL bills monthly.

Tips to reduce your TNEB bill

  • Confirm your eligibility for 100 free units (all domestic consumers) is correctly marked on your account — it's worth 100 free units every cycle.
  • Where practical, keep usage below your next slab threshold — the marginal units above ₹11.55/unit cost the most.
  • For high-usage households, rooftop solar can offset your most expensive top-slab units — see the solar section above.

Energy saving tips for Tamil Nadu electricity bills

Switch to BLDC ceiling fans

BLDC motors typically use 60–70% less power than a regular induction-motor fan for the same airflow.

Choose BEE 5-star rated appliances

A 5-star AC, refrigerator or washing machine can use 20–30% less electricity than a 1-star model of the same capacity.

Set your AC to 24°C or higher

Each degree below 24°C typically adds 3–5% to an AC's power draw — 24°C with a fan running is usually just as comfortable.

Switch to LED lighting

LED bulbs use roughly 80% less energy than incandescent bulbs for the same brightness, and last far longer.

Unplug appliances on standby

TVs, set-top boxes and chargers left plugged in can draw a small standby load around the clock — unplugging them when not in use adds up over a billing cycle.

Net metering explained

Net metering lets a rooftop solar system export surplus power back to the grid through your existing meter, which runs in reverse. At billing time, your DISCOM credits the exported units against what you drew from the grid — you're billed only for the net difference. Combined with telescopic slabs, this typically offsets your most expensive units first.

About TNEB

  • 1957 — Tamil Nadu Electricity Board (TNEB) formed as a single, vertically integrated utility.
  • 2010 — Restructured under the Electricity Act 2003 into three entities: TNEB Ltd (holding company), Tamil Nadu Generation and Distribution Corporation Ltd (TANGEDCO) for generation and distribution, and Tamil Nadu Transmission Corporation Ltd (TANTRANSCO) for transmission.
  • 2024 — TANGEDCO's distribution business renamed Tamil Nadu Power Distribution Corporation Ltd (TNPDCL).
  • Today — "TNEB", "TANGEDCO" and "TNPDCL" are all still used interchangeably on bills, signage and customer service.

Does TNEB (TANGEDCO/TNPDCL) supply electricity to Chennai?

Yes. Unlike cities such as Mumbai or Delhi, which have multiple private distribution licensees, Tamil Nadu has a single distribution utility covering the entire state — including Chennai, Coimbatore, Madurai, Tiruchirappalli, Tirunelveli, Salem and Vellore. There is no separate city-specific electricity board in Tamil Nadu.

How to check and pay your bill

  1. 1Visit the official TNPDCL website and select "Pay Online" under Online Payment Services
  2. 2Choose "Quick Pay" and enter your Consumer/Service Connection number
  3. 3Verify the displayed bill amount and pay via UPI, card or net banking
  4. 4Save the payment receipt/reference number for your records

Why use this calculator?

  • Free and instant — get an estimate in seconds, no signup or login required.
  • Real DISCOM tariff data — uses each state board's own published slabs, fixed charges, duty and FCA, not an all-India average.
  • Full itemised breakdown — see exactly how the energy charge, fixed charge, duty and any subsidy add up to your total.
  • Works both ways — enter units to get your bill, or enter a budget to see how many units it buys.
  • Available in English and Hindi everywhere, plus the state's own language for major states.
  • Kept current — every tariff page shows its effective-from and last-verified date, sourced from the DISCOM's own tariff order.

Available in Multiple Languages

This calculator is available in English, हिन्दी, தமிழ். Switch anytime using the language menu at the top of the page — no need to redo your inputs.

  • Same verified tariff data in every language — nothing is approximated in translation.
  • Switch languages anytime from the menu at the top of the page.
  • Available in English and Hindi on every state page, plus the local language for major states.

Frequently asked questions

How is my TNEB electricity bill calculated?

TNPDCL bills domestic consumers (tariff LA1A) bi-monthly. Free units come off first — 200 if the two-month total is 500 units or less, 100 if it is more — and the remaining units are billed slab by slab from ₹4.70 per unit. The result is rounded to a whole rupee. For 300 units the bill is ₹470.

What is TNEB's current tariff for domestic connections?

For a bi-monthly total up to 500 units: units 1–200 are free, 201–400 cost ₹4.70 and 401–500 cost ₹6.30. For a total above 500 units: units 1–100 are free, 101–400 cost ₹4.70, 401–500 ₹6.30, 501–600 ₹8.40, 601–800 ₹9.45, 801–1,000 ₹10.50, and units above 1,000 cost ₹11.55.

What changed between the old and new TNEB tariff?

The slab rates are the same. The change, from 10 May 2026, is the free allowance: 200 units, up from 100, for homes using up to 500 units in the cycle. A 300-unit bill fell from ₹940 to ₹470 and a 500-unit bill from ₹2,040 to ₹1,570. Bills above 500 units did not change.

What happens to my TNEB bill above 500 units?

Crossing 500 units removes the second 100 free units for the whole bill. A 500-unit bill is ₹1,570 and a 501-unit bill is ₹2,048, so one extra unit costs ₹478.

Is the TNEB bill monthly or bi-monthly?

The TNEB domestic bill is bi-monthly: it covers about 60 days, and the slabs and free units apply to that two-month total. This calculator also shows a monthly equivalent. TNPDCL’s own calculator has a separate Monthly option for a billing cycle of fewer than 35 days.

Is there a fixed charge on a TNEB domestic bill?

TNPDCL’s own bill calculator shows no fixed charge, fuel surcharge or electricity tax on a domestic bill. Commercial connections pay a fixed cost of ₹110 per kW per month and 5% electricity tax.

How do I calculate TNEB units from my meter reading?

Subtract the previous reading from the current reading; the difference is the units consumed in the cycle. Switch this calculator to "Meter reading" and enter both readings to get the units and the bill together.

How is a TNEB commercial bill calculated?

A commercial bill (tariff LM51) is charged at one rate for all units, not slab by slab: about ₹6.45 per unit when the bi-monthly total is up to 100 units and about ₹10.15 above that, plus ₹110 per kW per month, peak charges and 5% electricity tax, per TNPDCL’s calculator. The commercial option here is an approximation and runs low; use TNPDCL’s calculator for an exact commercial figure.

What's the difference between TNEB, TANGEDCO and TNPDCL?

TNEB (Tamil Nadu Electricity Board) was the original integrated utility until it was restructured on 1 November 2010 into TNEB Ltd (holding company), TANGEDCO (generation and distribution) and TANTRANSCO (transmission). On 27 June 2024, TANGEDCO’s distribution business was renamed Tamil Nadu Power Distribution Corporation Ltd (TNPDCL) — though “TNEB” and “TANGEDCO” both remain in everyday use for bills.

How do I check or pay my TNEB bill online?

Pay via the official TNPDCL portal at tnebnet.org, using the "Quick Pay" option with your service connection number. For outages, billing issues or meter problems, call the 24×7 helpline 1912.

How accurate is this TNEB bill calculator?

We checked the domestic results against TNPDCL’s own bill calculator on 10 October 2026 at 15 consumption levels from 100 to 1,200 units, and every result matched to the rupee. The verification date is shown on this page and is updated whenever the tariff changes.