Net metering calculator: your solar electricity bill, unit by unit
This net metering calculator works out an electricity bill for a home with rooftop solar. Enter the units your bidirectional meter shows as imported from and exported to the grid, any banked units carried forward from earlier bills, and your tariff — slabs or a flat rate, fixed charge, electricity duty and fuel surcharge. It shows the units billed, the banked surplus carried forward (or paid out at a settlement rate) and the amount payable, with every line of the working.
Add the generation from your inverter and it also shows what the same month would have cost without solar, and under each of the three arrangements regulators use — net metering, net billing and gross metering — so you can see why the choice matters. All rates are your own entries, because they differ from one DISCOM and tariff order to the next; currencies include ₹, Rs (Pakistan), ৳ (Bangladesh) and more.
How to use the Net Metering Bill Calculator
- Choose the arrangement on your connection: Net metering, Net billing or Gross metering.
- Enter the imported and exported units from the bill or meter (kWh), and for net metering the banked units brought forward.
- Optionally enter the solar generation reading from the inverter to see your saving and the comparison table.
- Enter the energy slabs or a flat rate, the fixed charge, duty and fuel surcharge from your tariff; for net billing or gross metering, the export rate.
- At the end of the settlement period, tick Settle the banked surplus and enter the settlement rate. Copy the summary to check against your bill.
Net Metering Bill Calculator features
Net meter calculation formula
Units billed = imported − exported − banked, never below zero; any surplus is carried forward or settled.
Three arrangements
Net metering, net billing (exports credited in money) and gross metering (all generation sold, all use bought), compared on the same month.
Slab tariff editor
Telescopic slabs with add and remove, or one flat rate, plus fixed charge, duty % and a per-unit fuel or FPPA surcharge.
Saving vs no solar
Consumption = imported + generation − exported, billed on the same tariff for an honest comparison.
Copyable working
Every slab, charge and credit line in a summary you can paste into a complaint or a spreadsheet.
Net metering vs net billing vs gross metering
In India the 2021 amendment to the Electricity (Rights of Consumers) Rules, 2020, notified by the Ministry of Power, allows net metering for prosumers with loads up to 500 kW or their sanctioned load, whichever is lower, and gross metering above that, with the detailed arrangements — banking period, settlement rate, net billing — set by each State Electricity Regulatory Commission. Check your state commission’s current regulation and tariff order for the numbers.
| Arrangement | What is netted | Bill formula |
|---|---|---|
| Net metering | Units: exports set off imports one for one; extra units are banked | tariff(imported − exported − banked) + fixed + duty |
| Net billing / net feed-in | Money: imports at the retail tariff, exports at a lower export rate | tariff(imported) + fixed + duty − exported × export rate |
| Gross metering | Nothing: all generation is sold, all consumption bought | tariff(consumption) + fixed + duty − generation × feed-in rate |
Worked example
A month with 320 units imported, 260 exported and 40 banked units brought forward: 320 − 260 − 40 = 20 units billed. On example slabs of ₹3 (first 100 units), ₹5 (101–300) and ₹7 (above 300) that is ₹60, plus 5 % duty (₹3) and a ₹100 fixed charge — ₹163.
The inverter showed 450 units generated, so the home used 320 + 450 − 260 = 510 units; without solar they would cost ₹3,008.50, a saving of ₹2,845.50. Under net billing with exports at ₹3 the same month would cost ₹832, and under gross metering ₹1,658.50 — net metering is worth most when the retail tariff is well above the export rate.
Reading a solar bill correctly
- The bidirectional meter records import and export separately; the inverter’s generation figure is not on the DISCOM bill.
- Fixed or demand charges are usually payable even when the net units are zero, so a net-metered bill rarely falls to nothing.
- Banked surplus is typically settled once a year at a rate fixed by the regulator, which is often far below the retail tariff — size the system to your use. The solar panel calculator sizes it from your bill and the solar subsidy calculator gives the PM Surya Ghar subsidy.
- Without solar, the electricity bill calculator estimates a bill from your appliances.
Net Metering Bill Calculator FAQ
What is the net meter calculation formula?
Units billed = units imported − units exported − banked units brought forward. If the result is negative, the extra units are carried forward to the next bill (or paid at the settlement rate at the end of the settlement period). The bill is the tariff on the billed units plus fixed charges and duty.
How do I calculate my electricity bill with solar net metering?
Read import and export from the bidirectional meter, subtract export and banked units from import, apply your slab tariff to what is left, then add the fixed charge, duty and any fuel surcharge. The net metering calculator does each step.
What is the difference between net metering and net billing?
Net metering offsets units against units, so every exported unit is worth a full retail unit. Net billing values exports in money at an export rate and charges every imported unit at the retail tariff.
Why do I still pay a bill with net metering?
Fixed or demand charges, meter rent and some duties are charged on the connection, not on units, so they remain even when exports cover your imports.
What happens to extra solar units at the end of the year?
Under most Indian state regulations the banked surplus is settled at the end of the settlement period at a rate set by the regulator. Tick Settle the banked surplus and enter that rate to see the credit.
Does this work for Pakistan or Bangladesh net metering?
The arithmetic is the same: choose Rs or ৳ as the currency and enter the import and export units, rates and charges from your utility’s bill.