Electricity Bill Unit Calculator
Calculate electricity consumption units and estimate your monthly/annual bill amount. Free, instant, and accurate.
For Indian Residents (ROR) earning overseas bank interest. NRIs: Your foreign interest is NOT taxable in India — use this calculator to see ₹0 Indian tax result. About Accuracy: This calculator uses FY 2025-26 tax rules including Section 5(1) (global income), Section 91 (Foreign Tax Credit), and New Regime slabs with surcharge and 4% cess. For methodology details, see our Accuracy & Limitations page.
Why Your Electricity Bill Confuses You (And How This Works)
An electricity bill is confusing to most people. You calculate units times cost per unit and the actual bill is always higher. The truth is, calculating an electricity bill in India involves more than multiplication. Tariffs are set by State Electricity Regulatory Commissions (SERCs), implemented by electricity distribution companies (DISCOMs), and adjusted for factors like consumption patterns, subsidies, fixed charges, and state-specific regulations.
This calculator estimates your electricity bill based on official FY 2025–26 tariff data published by SERCs and DISCOMs. It helps you understand how your bill is calculated, spot unusual charges, and verify you're being billed correctly. It's not your official bill, but it helps you estimate and verify.
How Electricity Tariffs Work in India
State Electricity Regulatory Commissions (SERCs)
Each Indian state has a SERC—an independent regulatory body that decides what electricity distribution companies can charge. When a DISCOM wants to change rates, it files a petition to the SERC. The SERC approves tariffs, which are published as "tariff orders." These are the official, legal rates DISCOMs must follow.
Why Tariffs Differ by State
Electricity tariffs in Maharashtra are different from Tamil Nadu, which are different from Delhi. This is because states have different generation costs (some have cheap hydropower, others rely on expensive thermal power), distribution losses (rural areas lose more electricity in transmission), subsidy policies, and fuel costs. Every state's SERC factors these into tariffs.
What Makes Up Your Bill
- Units (kWh): Kilowatt-hours consumed, measured by your meter
- Energy charges: The cost of electricity itself, often calculated using slab-based pricing
- Fixed charges: Monthly meter maintenance charges, paid regardless of consumption
- Subsidies: Many states reduce costs for low-income households
- Additional charges: Electricity duty, fuel adjustment charges, taxes, surcharges
Understanding Slab-Based Tariffs
Most Indian states use slab-based (progressive) tariffs. This means different ranges of consumption have different rates. The more you use, the more you pay per unit. This design encourages conservation.
Example: Domestic Slab Tariff
• 0–100 units: ₹3 per unit
• 101–200 units: ₹5 per unit
• 201–300 units: ₹7 per unit
• 301+ units: ₹9 per unit
If you consume 250 units: (100 × ₹3) + (100 × ₹5) + (50 × ₹7) = ₹1,150. You only pay ₹7 for units in that slab, not for all 250 units.
Not all states use slab-based tariffs. Some use flat rates (everyone pays the same per unit). Others use mixed systems. Check your state's SERC tariff to know which applies to you.
How This Electricity Bill Calculator Works
Step 1: You select your state or union territory. The calculator loads the SERC-approved tariff for that state for FY 2025–26.
Step 2: You select your meter category (domestic, commercial, industrial, agricultural). Each has different tariffs.
Step 3: You select your meter type (single-phase, three-phase) or capacity if applicable.
Step 4: You enter your meter readings. The calculator computes units consumed.
Step 5: For slab-based tariffs, it divides units across slabs, applies the correct rate to each slab, adds fixed charges and subsidies, then displays your estimated bill.
Important: This calculator does not store or send your meter readings. Everything is computed on your device in real-time. No data leaves your browser.
Accuracy & Why Your Actual Bill Might Differ
Data Source: This calculator uses official tariff data from State Electricity Regulatory Commissions and DISCOMs. It's not averaged or guessed.
Why Your Bill Might Be Higher:
- Fuel Adjustment Charges (FAC): Temporary charges when coal/energy costs spike
- Electricity Duty: State tax (4–10% of bill)
- Late Payment Surcharge: Added if you paid late
- Meter Rounding: Some meters round fractional units
- Time-of-Use Adjustments: For smart meters or solar connections
Data Updates: Tariffs change mid-fiscal year if there are subsidy changes or fuel cost spikes. Check your state's SERC website for the latest rates if you suspect a change.
Why Tariffs Vary by State and Category
Urban vs. Rural
Rural areas often have higher tariffs because of longer transmission lines and higher distribution losses. Urban areas have better infrastructure and lower cost per customer.
Subsidy Policies Vary
Tamil Nadu heavily subsidizes consumption up to 100 units. Delhi offers free electricity up to 200 units in some categories. Karnataka has tiered subsidies. Rajasthan has minimal subsidy. Know your state's policy.
Fixed Charges Vary by Meter Load
Some states charge a flat fixed amount. Others base it on your meter's capacity. A 15-amp meter pays more fixed charge than a 5-amp meter because infrastructure must support higher load.
Types of Electricity Tariff Structures in India
| Tariff Type | Explanation | Used In |
|---|---|---|
| Slab-based (Progressive) | Different rates for different consumption ranges. Higher usage incurs higher rates. | Maharashtra, Tamil Nadu, Karnataka, Delhi (most major states) |
| Flat-rate (Uniform) | Single rate per unit regardless of consumption. Simpler but doesn't incentivize conservation. | Some rural areas, small towns, certain DISCOM zones |
| Mixed Systems | Free/subsidized units for low consumption, then slab-based rates above threshold. | Most states with subsidies for poor households |
| Load-based Fixed Charges | Fixed charge varies based on meter capacity (load in kW/amps), not per consumer. | Karnataka, Maharashtra (certain categories) |
Frequently Asked Questions
Q: Why is my actual bill higher than this calculator shows?
A: This calculator shows energy charge plus fixed charge and subsidies. Your actual bill typically includes electricity duty (4–10%), fuel adjustment charges (if coal costs spike), surcharges, and meter rounding. Ask your DISCOM for a breakdown to see these extra components.
Q: What is "slab-based pricing" and why does it exist?
A: It's a tariff structure where the cost per unit increases as your consumption increases. The first 100 units might cost ₹3/unit, the next 100 might cost ₹5/unit, and above that ₹7/unit. Only the units within each slab are charged at that slab's rate. This design encourages conservation and helps make electricity affordable for poor households that use very little.
Q: Are subsidies included in this calculator?
A: Yes, if your state's published tariff includes subsidies for your consumption level. For example, if your state subsidizes consumption up to 100 units, the calculator applies that subsidy. Check your state's SERC tariff order to confirm whether subsidies apply to your meter category.
Q: Why does my neighbour pay less if we consume similar units?
A: Possible reasons: (1) Different meter categories (commercial vs. domestic); (2) Different subsidy eligibility; (3) Different fixed charges based on meter capacity; (4) Your neighbour might have a lower-rated meter, so lower fixed charge; (5) Different billing cycle (late fees); (6) Different tariff zone (urban vs. rural, or different DISCOM).
Q: How often do tariffs change?
A: SERCs typically revise tariffs once per fiscal year (April to March). Mid-year changes happen only if there are significant cost spikes (fuel adjustment) or new subsidy schemes. This calculator is updated with the latest tariffs as soon as they're published by SERCs.
Q: Why do I have to pay fixed charges even when I use very little?
A: Fixed charges cover the cost of maintaining your meter, the wires to your home, billing systems, and customer service. These costs exist whether you use 10 units or 100 units. It's like a subscription fee for access to the electricity grid. Most SERCs consider this fair because everyone benefits from grid access.
Q: Can I reduce my electricity bill?
A: Yes. Reduce consumption: use LED bulbs (75% less than incandescent), set AC to 24–26°C (saves 4% per degree), unplug devices when not in use, use fans instead of AC in mild weather, and keep appliances well-maintained. You can also check if you're eligible for new subsidy schemes or if your state offers time-of-use rates with cheaper off-peak hours.
Q: What should I do if my bill seems wrong?
A: First, verify your meter reading by comparing it with the reading on your bill. Use this calculator with the same meter reading to see what the charge should be. If there's still a big difference, contact your DISCOM's customer service. They'll investigate. If dissatisfied, file a complaint with your state's SERC.
Q: Is this calculator accurate for commercial or industrial meters?
A: Less so. Commercial and industrial tariffs are highly variable and often depend on specifics like load factor, demand (kVA), or time-of-use patterns. This calculator handles basic commercial tariffs but not all edge cases. For precise commercial billing, contact your DISCOM directly.
Q: Why should I trust this calculator?
A: Because it uses official SERC tariff data, not averages or estimates. SERCs are independent regulators; their tariffs are transparent and public. This calculator applies slab logic transparently. You can verify the tariff numbers on your state's SERC website. However, this is a tool for estimation and verification, not a replacement for your official DISCOM bill.
Q: How do I read my electricity meter correctly?
A: Look at the numerical display (usually 5–6 digits). Note the number as it is shown. Compare it with last month's reading to calculate units consumed (current reading minus previous reading equals units used). Record it before your meter gets reset or tampered with.
Tips to Manage Your Electricity Bill
Track your consumption monthly
Note your meter reading every month. Plot it on a spreadsheet. Unusual spikes reveal problems (meter malfunction, appliance failure, or usage surge). Catching this early helps you act before the big bill arrives.
Audit your appliances
The biggest energy consumers: AC (40–50% of bill), water heater, refrigerator, washing machine. If you're on a high bill, check if these are running efficiently. A 10-year-old AC uses 20% more energy than a new 5-star model.
Switch to LED bulbs
A 60-watt incandescent bulb uses 60 watts per hour. A 10-watt LED produces the same light using 10 watts. Over a month, that's significant savings per bulb. The upfront cost is recovered in 6–12 months.
Optimize AC usage
For every degree you lower the thermostat below 24°C, consumption increases about 4%. Set it to 24–26°C. Use ceiling fans to circulate cool air. Close doors and windows. Service your AC annually.
Use appliances efficiently
Run the washing machine and dishwasher with full loads. Defrost your refrigerator regularly. Use a pressure cooker instead of a regular pot. Use a microwave for small portions instead of an oven. Small habits compound into big savings.
Check for subsidies and schemes
Some states offer subsidies for poor households, senior citizens, disabled persons, or farmers. Some offer incentives for rooftop solar. Check your state's SERC website or DISCOM's website for schemes you might be eligible for.
Know your tariff
Read your DISCOM's tariff schedule. Understand the slabs, fixed charges, and special rates. Knowledge is power. Many disputes arise from misunderstanding, not actual errors.
Verify your bill every month
Before paying, spend two minutes to verify: Check meter reading matches yours. Check it's within the expected range of last month. Check for unusual charges. Most billing errors are simple mistakes that take seconds to spot.
About Tariff Data & Updates
This calculator uses tariff data compiled from State Electricity Regulatory Commissions (SERCs) and DISCOMs across India. The data reflects official FY 2025–26 tariffs.
Data is updated when: SERCs publish new tariff orders (typically annually), DISCOMs announce mid-year changes, or new subsidy schemes are notified by state governments.
To verify tariff data yourself: Visit your state's SERC website (search "[Your State] SERC") or your DISCOM's website. Look for the latest "Tariff Order" or "Schedule of Charges" document for the current fiscal year.
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