Claire WhitakerBy Claire Whitaker

Updated November 2026

To calculate a net metering bill, you subtract the electricity your solar system exports to the grid from the electricity you import from the grid, then apply your utility’s rates and credit rules to the difference. Once you know your import and export readings for the billing period, you can work out your net usage and the dollar amount you owe, or the credit you carry forward. This guide walks through each step using the same logic most utilities follow.

Gather Your Meter Readings and Billing Period

Every net metering bill is built from readings taken at the start and end of the billing cycle, usually about 30 days apart. Most homes with solar have a bidirectional meter that tracks two separate totals: kilowatt-hours (kWh) pulled from the grid and kWh pushed back to it. Your utility portal or monthly statement lists both.

Shopping for one? See our guide: Dominion Power Net Metering (2026): How It Works and Who Benefits.

  1. Note the opening and closing import reading (kWh drawn from the grid).
  2. Note the opening and closing export reading (kWh sent to the grid).
  3. Subtract each opening reading from its closing reading to get the monthly import and export totals.
  4. Confirm the number of days in the billing period so you can compare months fairly.

Calculate Your Net kWh Usage

Net usage is the simple difference between what you bought and what you sent back. If your import total is higher than your export total, you have a net balance to pay for. If exports are higher, you have surplus energy that usually becomes a credit.

Use this formula:

Net kWh = Imported kWh − Exported kWh

For example, if you imported 620 kWh and exported 480 kWh in a month, your net usage is 140 kWh. You would pay for 140 kWh at your applicable rate, minus any fixed monthly charges.

Apply Your Utility Rate and Credit Rules

The net kWh figure only becomes a dollar amount after you apply your rate schedule. Check whether your utility bills at a single flat rate or uses time-of-use pricing, because exports during peak hours may be credited differently than exports during off-peak hours. Some utilities also apply a buyback rate to surplus exports rather than a full retail credit. The rules differ by state and provider, so confirm yours in your tariff document. For a deeper look at how credits are valued, see Net Metering Buyback Rate: How to Find Yours and Calculate Your Credit.

A typical calculation looks like this:

Step What to Do Example Value
1 Find total imported kWh 620 kWh
2 Find total exported kWh 480 kWh
3 Subtract exports from imports 140 kWh net
4 Multiply net kWh by your energy rate Varies by utility
5 Add fixed charges and fees Listed on your bill

Handle Surplus Credits and Carryover

When exports exceed imports for the month, many programs carry the extra kWh forward as a credit against future usage. Others pay out the surplus once a year at a set rate. Check whether your credits roll over monthly or annually, and whether any unused balance expires. Understanding this is the difference between a small bill and an unexpected one. If your bill still looks high after you run the numbers, Why Is My Net Metering Electricity Bill Still High? 6 Causes and Fixes covers the most common reasons.

Common Mistakes to Avoid

  • Mixing up import and export columns, which reverses the result.
  • Using a single month’s data when your usage is seasonal. Compare at least 12 months for a fair picture.
  • Forgetting fixed monthly charges, which apply even when your net usage is zero.
  • Assuming every kWh is credited at the same rate when your utility uses time-of-use pricing.
  • Ignoring the billing period length, which can make two months look different when they are not.

FAQ

Can my net metering bill be zero?

Yes, if your exports match or exceed your imports for the period. Many utilities still charge a monthly connection or service fee, so a zero energy charge may not mean a zero bill.

Why does my bill differ from my own calculation?

Differences usually come from time-of-use rates, buyback pricing on exports, or fees not included in your simple kWh math. Compare your numbers line by line against the statement.

Where can I find the exact import and export readings?

Your utility’s online account portal typically shows both readings for each billing cycle. Your monthly statement also lists them, often under a meter reading or usage section.

Conclusion

To calculate a net metering bill, subtract exported kWh from imported kWh, then apply your utility’s rates and credit rules. Checking your readings each month will help you spot errors and understand your savings. When in doubt about your tariff or contract terms, contact your utility or a licensed solar professional.

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Claire Whitaker

About Claire Whitaker

Claire Whitaker is part of our editorial team and reviews and edits our home solar guides, checking product details against manufacturer specifications and owner feedback.