Calculate your bill
Electricity Bill Calculator
Accurate estimates for Tamil Nadu · TNEB
Estimated bi-monthly bill
₹777.50
≈ ₹388.75 / month (125 units)
| 1–100 @ ₹2.25 × 100 | ₹225.00 |
| 101–200 @ ₹3.5 × 100 | ₹350.00 |
| 201–500 @ ₹4.8 × 50 | ₹240.00 |
| Energy charge | ₹815.00 |
| Subsidy applied | −₹225.00 |
| Fuel cost adjustment (₹0.35/unit) | ₹87.50 |
| Fixed charge (single-phase) | ₹100.00 |
| Total | ₹777.50 |
Worked example
A 250-unit bi-monthly Tamil Nadu residential bill (single-phase) works out to ₹012345678901234567890123456789 — about ₹388.75 per month. That is ₹815.00 energy charge − ₹225.00 subsidy + ₹87.50 FCA + ₹100.00 fixed charge.
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
You can use up to
293 units
for a bi-monthly bill of ₹998.95 (within your ₹1,000.00 budget)
How to use this calculator
- 1Select your state — it's pre-selected for this page
- 2Enter the units consumed shown on your bill, or your meter readings
- 3Choose your connection phase (single or three) if applicable
- 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 100-unit subsidy line
0–100 units
Free
101+ units
Metered from ₹2.25
Eligible domestic consumers get the first 100 units of every bi-monthly cycle free. Units beyond 100 are billed telescopically starting at the same ₹2.25 rate — crossing 100 units does not cancel the subsidy already applied to the first 100.
Tamil Nadu residential tariff slabs
| Slab (units) | Rate (₹/unit) |
|---|---|
| 0–100 | ₹2.25 |
| 101–200 | ₹3.50 |
| 201–500 | ₹4.80 |
| 501–above | ₹6.40 |
| Fixed charge | ₹100 / ₹200 (single / three-phase) |
| Fuel cost adjustment | ₹0.35/unit |
Effective from 1 April 2026 · Verified 29 August 2026 · source order
Two worked examples
Lower usage
₹777.50
250 units · ₹815.00 energy − ₹225.00 subsidy + ₹100.00 fixed + ₹87.50 FCA
Higher usage
₹2,740.00
600 units · ₹2,655.00 energy − ₹225.00 subsidy + ₹100.00 fixed + ₹210.00 FCA
Common TNEB bill traps
The 100-unit "all or nothing" myth
Some people assume that using more than 100 units forfeits the free-unit subsidy entirely. It doesn't — the first 100 units are deducted at the ₹2.25 rate regardless of your total consumption for the cycle, so a 300-unit bill still gets the same ₹225 reduction as a 100-unit bill.
Phase mismatch on the fixed charge
TNEB's fixed charge depends on your connection phase, not your sanctioned load: ₹100 for single-phase, ₹200 for three-phase, per bi-monthly cycle. If your household has a three-phase connection (common for homes with higher-capacity ACs or motors), your fixed charge is double what a single-phase neighbour pays.
The summer slab jump
Running an AC through summer often pushes consumption from the ₹3.50/unit band into the ₹4.80/unit band. Only the units above 200 are charged at the higher rate — it's not retroactive — but the marginal jump surprises people comparing a summer bill to a winter one.
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
TANGEDCO reads domestic meters once every two months, so a TNEB bill covers roughly 60 days. All slab limits and the free-unit allowance apply to that two-month total — the single biggest source of confusion when comparing to a monthly bill.
Free-unit subsidy
Eligible domestic consumers receive the first 100 units of each cycle free, deducted at the lowest slab rate (₹2.25/unit).
Fuel cost adjustment (FCA)
A ₹0.35/unit surcharge reflects TANGEDCO's power-purchase costs, added on top of the slab energy charge along with a phase-based fixed charge.
Your bill, component by component
Based on the 250-unit example above. Expand each line for what it means and whether you can influence it.
Energy chargeReducible₹815.00+
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 ₹815.00.
SubsidyWorth checking₹225.00+
100 Units Free Domestic Subsidy (LT-IA) reduced this bill by ₹225.00. This is the one line worth double-checking against your paper bill — confirm your eligibility status is correctly marked.
Fuel cost adjustment (FCA)Set by DISCOM₹87.50+
A ₹0.35/unit pass-through surcharge that tracks the DISCOM's power-purchase cost. It applies equally to every consumer on this tariff and isn't something you can reduce by changing usage.
Fixed chargeFixed₹100.00+
Charged regardless of how many units you use (single-phase). The only way to change this line is to change your phase, sanctioned load, or connection type.
What's included in your bill
| Component | What it is | Typical range |
|---|---|---|
| Energy charge | Units × slab rate, telescopic | ₹2.25–₹6.40/unit |
| Fuel cost adjustment | Pass-through fuel surcharge | ₹0.35/unit |
| Fixed charge | Flat, independent of usage | ₹100 / ₹200 (single / three-phase) |
| Subsidy | 100 Units Free Domestic Subsidy (LT-IA) | 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.
☀️ See how much solar could save you in Tamil Nadu
Rooftop solar can cut this bill sharply. Check your payback period and PM Surya Ghar subsidy in under a minute.
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 ₹88.70/year at Tamil Nadu's top slab rate (₹6.75/unit) — per bulb.
Upgrade to a 5-star AC
A 1.5 ton 5-star AC vs 3-star, run 6 hrs/day, saves about ₹3,762.54/year in Tamil Nadu.
See the full comparison →How does TNEB compare?
TNEB
Tamil Nadu
Top slab rate
₹6.40/unit
Base slab
₹2.25
Slabs
4
Billing
bi-monthly
Duty
0%
KSEB
Kerala
Top slab rate
₹8.50/unit
↑ 33% costlier than TNEB
Base slab
₹3.35
Slabs
6
Billing
bi-monthly
Duty
5%
BESCOM
Karnataka
Top slab rate
₹8.60/unit
↑ 34% costlier than TNEB
Base slab
₹5.90
Slabs
3
Billing
monthly
Duty
0%
APSPDCL
Andhra Pradesh
Top slab rate
₹9.75/unit
↑ 52% costlier than TNEB
Base slab
₹1.90
Slabs
6
Billing
monthly
Duty
0%
Top Slab Rate Comparison
TNEB's top domestic slab rate is ₹6.40/unit — more expensive than KSEB (₹8.50/unit), — more expensive than BESCOM (₹8.60/unit), — more expensive 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 Units Free Domestic Subsidy (LT-IA) 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 ₹6.40/unit cost the most.
- The ₹0.35/unit fuel cost adjustment applies to every unit you use, so reducing overall consumption reduces this line too — unlike the fixed charge.
- For high-usage households, rooftop solar can offset your most expensive top-slab units — see the solar section above.
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. Estimate your solar payback →
About TNEB
Tamil Nadu Electricity Board (TNEB) was formed on 1 July 1957 as a single, vertically integrated utility. On 1 November 2010, under the Electricity Act 2003, it was restructured 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.
On 27 June 2024, TANGEDCO's distribution business was renamed Tamil Nadu Power Distribution Corporation Ltd (TNPDCL). Both "TANGEDCO" and the older "TNEB" name remain in everyday use — on bills, signage and customer service — alongside the newer TNPDCL name.
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
- 1Visit the official TANGEDCO/TNEB website and select "Pay Online" under Online Payment Services
- 2Choose "Quick Pay" and enter your Consumer/Service Connection number
- 3Verify the displayed bill amount and pay via UPI, card or net banking
- 4Save the payment receipt/reference number for your records
Official portal
tnebnet.org (official TANGEDCO payment portal)
Helpline
1912 (24×7) · 044-28521109
Frequently asked questions
How is my TNEB electricity bill calculated?
TANGEDCO bills residential (LT-IA) consumers bi-monthly. Your bill is the sum of telescopic slab-wise energy charges, plus a ₹0.35/unit fuel cost adjustment (FCA) and a phase-based fixed charge, minus the 100-unit free subsidy if you qualify.
What is TNEB's current tariff for domestic (LT-IA) connections?
Telescopic slabs of ₹2.25/unit (0–100), ₹3.50/unit (101–200), ₹4.80/unit (201–500) and ₹6.40/unit (501+), plus a fixed charge of ₹100 single-phase or ₹200 three-phase per bi-monthly cycle.
Why is my TNEB bill bi-monthly instead of monthly?
TANGEDCO reads domestic meters once every two months, so a bill covers roughly 60 days rather than 30. To compare against a "monthly" figure, divide the bi-monthly total by two — this calculator does that automatically as the monthly-equivalent.
Do I get free electricity units from TNEB?
Eligible domestic consumers get the first 100 units of each bi-monthly cycle free, valued at the ₹2.25 lowest-slab rate — a flat ₹225 reduction, not a percentage discount. It applies regardless of how many total units you use in the cycle.
What is Fuel Cost Adjustment (FCA) and why is it on my bill?
FCA is a per-unit surcharge, currently ₹0.35/unit, that reflects TANGEDCO’s changing power-purchase cost. It is separate from and added on top of the slab energy charge.
How can I reduce my TNEB electricity bill?
Confirm your 100-unit subsidy eligibility is correctly marked on your account, and keep usage below your next slab threshold where practical — the jump from ₹3.50 to ₹4.80/unit at 200 units is the most common one people cross unintentionally in summer.
Is solar worth it for a typical TNEB household?
Often yes — TNEB’s top domestic slab (₹6.40/unit) is high enough that a rooftop system can offset your most expensive units first. Use our solar ROI calculator, pre-filled for Tamil Nadu tariffs, to see your payback period.
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 TANGEDCO/TNEB portal at tnebnet.org, or through the TANGEDCO website’s "Pay Online" → "Quick Pay" option. For outages, billing issues or meter problems, call the 24×7 helpline 1912.
How often are TNEB tariff rates updated, and how do you keep this calculator accurate?
TNERC reviews domestic tariffs periodically, with CPI-linked adjustments typically each July. We record the source order URL and a last-verified date on every tariff file — visible at the bottom of this page — and update the data whenever a new order is issued.