Bill Calculations, Gas Costs and Checklists
How to reduce your electricity bill in India - a slab-aware checklist
Practical steps that cut a household electricity bill: stay under slab and subsidy thresholds, right-size sanctioned load, check surcharges, shift load and fix leaks.
The fastest way to cut an Indian electricity bill is to aim at the units charged at your highest slab, because every unit you save comes off the top. After that, check the parts that have nothing to do with consumption: a sanctioned load higher than you need, a missing subsidy registration, a wrong tariff category, or an estimated reading. Only then look at appliances, starting with the ones that run longest or hottest: cooling, water heating, pumps and old refrigerators. This checklist runs in that order, with rupee examples using the Delhi DERC and Tamil Nadu TNERC schedules.
Part of electricity bill calculation worked examples.
1. Find your top slab
From your last 12 bills, note monthly (or bi-monthly) units. Mark which slab the last units fall into in each period.
| Typical use | Top slab (Delhi monthly) | Value of saving 50 units |
|---|---|---|
| 180 units | 0–200 at ₹3.00 | ₹150 (but may be fully subsidised) |
| 350 units | 201–400 at ₹4.50 | ₹225 |
| 600 units | 401–800 at ₹6.50 | ₹325 |
| Typical use (two months) | Top slab (Tamil Nadu, TNERC T.O. 6/2025, before subsidy) | Value of saving 50 units |
|---|---|---|
| 450 units | 401–500 at ₹6.65 | ₹333 |
| 700 units | 601–800 at ₹9.95 | ₹498 |
| 1,100 units | above 1,000 at ₹12.15 | ₹608 |
Add the fuel surcharge and duty on top: a 15–18% surcharge raises the value of each unit saved by the same share.
2. Watch the thresholds
Subsidy schemes have thresholds where the bill jumps. In Delhi, the full subsidy stops above 200 units a month and the 50% subsidy stops above 400. In Karnataka, Gruha Jyothi ends above 200 units. If you are close to a threshold, a few units saved in a hot month can be worth hundreds of rupees. See free electricity schemes.
3. Fix the non-consumption items
| Check | Possible saving | How |
|---|---|---|
| Sanctioned load too high | Fixed charge per kW each month | Apply for load reduction; see fixed charges |
| Subsidy not registered | Up to the full bill in some states | Register through the DISCOM or state portal |
| Wrong category (e.g. commercial) | Difference between commercial and domestic rates | Written request with proof of residential use |
| Estimated readings | Avoid slab bunching | Send meter photos; give the reader access |
| Late payment surcharge | Avoidable entirely | Use auto-pay or reminders |
| Prompt or digital payment rebate | Small but free | Check whether your tariff order offers one |
Illustrative: reducing sanctioned load from 6 kW to 5 kW on the Delhi schedule moves you from ₹100 per kW to ₹50 per kW: ₹600 down to ₹250 a month, saving ₹350 a month before surcharge.
4. Appliances that matter most
| Appliance | Why it matters | Practical step |
|---|---|---|
| Air conditioners | Large load, long hours in summer | Set 24–26°C, clean filters, use a fan with it, shade the outdoor unit |
| Geysers and immersion rods | 2–3 kW each | Use a timer; heat only before use; insulate pipes |
| Water pumps | Run longer than needed if there is a leak or no float switch | Fit an automatic level controller; fix tank leaks |
| Old refrigerators | Run all day; worn door seals | Replace seals; keep space behind for airflow; consider a BEE star-rated replacement when due |
| Coolers | Pump and fan all day | Clean pads; use with cross-ventilation |
| Lighting | Many hours | LED throughout |
| Standby loads | TV, set-top box, chargers | Switch off at the socket at night |
AC and geyser choice and running costs are a large topic of their own; focus here on use habits.
5. Shift load if you have a ToD tariff
If your bill shows time-of-day blocks, move washing, pumping, ironing and EV charging into solar hours. See time-of-day tariff rules.
6. Check for leakage and wiring faults
Switch off every appliance and the main switch inside the house, then watch the meter. If it still records consumption (on an electronic meter, the pulse LED keeps blinking), there may be leakage in wiring, a faulty appliance, or a connection beyond your premises using your supply. Ask a licensed electrician to test the wiring and fit or check an RCCB/ELCB, which is also a safety measure.
7. Consider rooftop solar
If your roof is shade-free and your top slab is expensive, rooftop solar under PM Surya Ghar can cut the units you are billed for. Test the economics first with the rooftop solar payback calculator and read PM Surya Ghar and net metering.
8. Cooking energy
Cooking on LPG, PNG or induction each has a different cost. Induction units land on your top slab. Compare with LPG cost per month and PNG versus LPG.
Worked example: a Delhi household at 450 units
Without changes: 200 × 3 + 200 × 4.50 + 50 × 6.50 = ₹1,825 energy charge, no subsidy above 400 units.
After setting the AC to 25°C and putting the geyser on a timer, use falls to 390 units: 200 × 3 + 190 × 4.50 = ₹1,455. The energy charge drops by ₹370, and the household is back in the 201–400 band where the 50% subsidy applies (if registered), roughly halving the bill. In Tamil Nadu, test your own two-month units in the electricity bill calculator.
Frequently asked questions
Do "power saver" plug-in devices reduce my bill?
Household meters bill real energy in kWh, and plug-in devices sold as power savers generally cannot reduce real consumption in a home. Spend the money on LED lamps, a timer or a water-level controller instead.
Does switching off the main at night save money?
It removes standby use, which is small but real. Do not switch off the refrigerator for long periods; food safety matters more.
Is it worth reducing my sanctioned load?
If your recorded maximum demand is well below your sanctioned load and your DISCOM charges per kW, usually yes. Check the DISCOM's rules on how often you can change it.
Sources and where to check
- Bureau of Energy Efficiency — star labelling and appliance efficiency
- Delhi Electricity Regulatory Commission — Delhi tariff schedule
- TNPDCL — Tamil Nadu tariff order and bill calculator
- Ministry of Power — consumer rights and energy conservation programmes
