How to calculate a tenant's electricity bill from meter readings
Billing a tenant for electricity means taking the difference between two sub-meter readings, applying the effective rate from the licensee's bill for the building, and adding a stated share of common-area consumption. The arithmetic is simple; disputes come from estimated readings, meter multipliers, resets, applying a flat invented rate, and folding unexplained amounts into the total instead of showing them as lines.
The method
Same every month, which is most of what makes it trustworthy.
- Record the closing reading on the tenant's sub-meter, with the date. Photograph the meter face.
- Subtract the previous closing reading. That difference is the units consumed.
- If the meter has a multiplier, apply it. Most domestic sub-meters do not, but a current-transformer meter will.
- Work out the effective rate from the licensee's bill: total amount billed divided by total units on the main meter.
- Multiply the tenant's units by the effective rate.
- Add the tenant's stated share of common-area consumption, calculated on the basis your agreement specifies.
- Show every one of those figures on the bill you issue, not just the total.
A worked example
Building bill ₹14,000 for 1,600 units. Tenant's sub-meter went from 4,120 to 4,300. Common-area load 120 units, split equally between four units of accommodation.
| Line | Working | Amount |
|---|---|---|
| Closing reading | 4,300 | — |
| Opening reading | 4,120 | — |
| Units consumed | 4,300 − 4,120 | 180 |
| Effective rate | ₹14,000 ÷ 1,600 | ₹8.75 |
| Energy charge | 180 × ₹8.75 | ₹1,575.00 |
| Common-area share | 120 ÷ 4 = 30 units × ₹8.75 | ₹262.50 |
| Total electricity for the month | ₹1,837.50 |
Because the effective rate comes from the whole bill, fixed charges and duties are already inside it and should not be added again separately. Adding them twice is a common and invisible error.
The six things that actually cause disputes
Estimated readings. A month where nobody read the meter and a figure was assumed is a month that will be argued about later, because the next real reading has to absorb the difference. Read it, or carry the balance openly instead of guessing.
A meter that resets or is replaced. When a meter rolls over to zero or is changed, the subtraction stops working and produces either a negative number or an enormous one. Note the final reading of the old meter and the starting reading of the new one, with the date, and bill the two periods separately.
An invented flat rate. Applying a round figure per unit is the most frequent cause of a tenant feeling overcharged, and if it sits above your actual effective rate they are right.
Charging fixed charges twice. If the effective rate is derived from the total bill, it already contains them.
Unexplained common-area amounts. A share of the staircase and pump load is perfectly fair; an unlabelled addition to the total is not, and reads as a markup.
No record of readings. Without dated photographs of the meter face, a disagreement about the opening reading cannot be settled, and the person without the record loses it.
Keep the bill in one shape
The format matters as much as the arithmetic. A tenant who receives the same six lines every month will notice immediately if one of them moves, and will accept the total because they can check it. A tenant who receives a single figure has nothing to check and will question it the first month it rises.
So issue it as lines: opening reading, closing reading, units, rate, common-area share, total. Keep a copy. At the end of the tenancy that record is also what lets you settle unpaid electricity against the deposit without an argument, because the amount is already documented and was accepted at the time.
Free tools you can use
Electricity calculation FAQ
How do I calculate a tenant's electricity bill from meter readings?
Subtract the previous sub-meter reading from the current one to get units consumed, apply the meter multiplier if it has one, multiply by the effective rate from the licensee's bill for the building, and add the tenant's stated share of common-area consumption. Show each figure on the bill rather than only the total.
What rate should I multiply the units by?
The effective rate, which is the licensee's total bill for the building divided by the total units on the main meter. That already includes fixed charges and duties in the right proportion, so they should not be added again. A round invented figure is almost never the actual cost per unit.
Should fixed charges be added separately?
Not if your rate came from dividing the total bill by total units, because they are already inside that rate. Adding them again is one of the easiest errors to make and one of the hardest for a tenant to spot.
What do I do when the sub-meter is replaced or resets to zero?
Record the final reading of the old meter and the opening reading of the new one, both with the date, and bill the two periods separately. Subtracting across a reset gives either a negative figure or an impossibly large one.
How should common-area electricity be split?
On a basis stated in the agreement, commonly equally per unit of accommodation or by occupancy, and shown as its own line on the bill. The main meter will always exceed the sum of the sub-meters because of staircase lighting, pumps and losses, so the gap has to be apportioned openly rather than absorbed into the rate.
What if I did not read the meter one month?
Do not estimate silently. Either read it late and bill the actual period, or state plainly that the figure is provisional and will be corrected against the next real reading. An estimate presented as a reading is what the next dispute will be about.
On RentStalk
Provisions referred to
- The Electricity Act, 2003 — Section 12 (no distribution or trading in electricity without a licence), which is why the rate must be cost recovery
- Tariff orders of the relevant State Electricity Regulatory Commission, which set the slab structure and fixed charges
This is general information, not legal or tariff advice. Slab structures, fixed charges and duties are set by each State Electricity Regulatory Commission and revised periodically, so check your current bill and tariff order rather than relying on the figures in the example.