Net Metering Calculator

Enter your solar production, consumption, and export credit rate — get your annual net metering savings with a month-by-month breakdown.

Your solar & usage data

Monthly solar production?

kWh/mo

Monthly electricity consumption?

kWh/mo

Electricity rate?

$/kWh

Net metering credit rate?

$/kWh

Annual net metering benefit

$1,723.50/year

Annual bill savings$1,836.00

Export credits earned$114.00

Grid electricity cost$226.50

Solar offset97%

Grid dependency3%

Without solar (annual)$2,062.50

Monthly breakdown (estimated seasonal variation)

Month	Solar kWh	Used kWh	Net export	Benefit
Jan	780	1,265	-485	$44.25
Feb	900	1,210	-310	$88.50
Mar	1,080	1,100	-20	$159.00
Apr	1,260	990	+270	$175.50
May	1,380	1,045	+335	$190.25
Jun	1,440	1,210	+230	$204.50
Jul	1,416	1,320	+96	$207.60
Aug	1,344	1,265	+79	$197.65
Sep	1,200	1,100	+100	$175.00
Oct	1,020	990	+30	$151.50
Nov	840	1,045	-205	$95.25
Dec	720	1,210	-490	$34.50

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How to Use This Calculator

Enter your monthly solar production

Find your monthly solar production in kWh on your solar monitoring app (Enphase Enlighten, SolarEdge monitoring, or your inverter's app) or on your utility bill. If you don't have a system yet, use the Solar Panel Calculator to estimate annual production and divide by 12 for a monthly average.

Enter your monthly consumption

Your monthly electricity consumption is on your utility bill — usually labeled "kWh used," "energy charges," or "consumption." The US average is about 900 kWh/month. If you've added an EV or electric heat recently, use your current bill, not a historical average.

Set electricity rate and credit rate

The electricity rate is what you pay per kWh drawn from the grid. The net metering credit rate is what your utility credits per kWh you export. In states with full net metering (California, New Jersey, New York), the credit rate equals the retail rate. Many utilities pay wholesale rates (5-10 cents) — check your interconnection agreement or utility website. The difference between these two rates is the key factor in net metering value.

Read the monthly table

The monthly breakdown uses typical seasonal variation — solar production peaks in summer, consumption peaks in summer (AC) and winter (heating). Winter months typically show grid imports; summer months show the most export credit. The total annual benefit is the sum of avoided grid purchases plus export credits earned.

The Formula

For each month: If Solar > Consumption: Savings = Consumption × Retail rate Credits = (Solar − Consumption) × Credit rate If Solar < Consumption: Savings = Solar × Retail rate Grid cost = (Consumption − Solar) × Retail rate Annual benefit = Sum of monthly (Savings + Credits − Grid cost) Solar offset (%) = Annual solar production ÷ Annual consumption × 100

The seasonal multipliers in the calculator are based on typical US solar irradiance and consumption patterns. Solar production peaks in June-July (~120% of annual average) and troughs in December (~60%). Consumption peaks in July-August (AC) and January-February (heating), and dips in spring and fall. Your actual seasonality depends on your location and home heating/cooling type.

Example

The Martinez family — San Diego, full net metering

The Martinez family has a 10kW solar system producing 1,200 kWh/month on average. They consume 1,100 kWh/month. San Diego Gas & Electric charges $0.40/kWh retail (one of the highest in the US) and pays $0.40/kWh export credit under full NEM.

Monthly solar production1,200 kWh

Monthly consumption1,100 kWh

Retail rate$0.40/kWh

Export credit rate$0.40/kWh (full NEM)

Annual result

Annual bill savings$5,280

Export credits$480

Total annual benefit$5,760

Without solar (annual)$5,280

The Martinez family essentially pays nothing for electricity — their solar covers 109% of consumption annually, and the export credits from summer surplus offset any winter grid purchases. At $5,760/year in savings on a $30,000 system (after 30% ITC = $21,000 net), payback is about 3.6 years — exceptional by any metric.

FAQ

What is net metering and how does it work? ▼

Net metering is a billing mechanism where your electric meter runs backward when your solar panels produce more electricity than you use. Excess electricity flows to the grid and you receive a credit on your bill. At night or on cloudy days, you draw from the grid and your meter runs forward. Your utility bill reflects the net difference — hence "net metering." Most states require utilities to offer net metering, but policies vary significantly on credit rates and annual true-up rules.

What is the difference between full net metering and net billing? ▼

Full net metering credits your exported kWh at the full retail rate — exactly what you pay to buy from the grid. This makes solar very valuable since 1 kWh exported equals 1 kWh avoided. Net billing (sometimes called NEM 3.0 in California) credits exports at a lower rate — often the wholesale or avoided-cost rate (5-10 cents/kWh) while you still pay retail rates to import. Net billing reduces the value of daytime excess and increases the value of batteries (by shifting production to evening peak hours).

Should I oversize my solar system to maximize export credits? ▼

It depends on your credit rate. At full net metering (credit = retail rate), oversizing is financially neutral — you earn the same per kWh whether you use it or sell it. At reduced credit rates (like $0.08/kWh credit vs $0.15/kWh retail), excess production beyond your consumption earns less per kWh than self-consumed solar. In that case, size your system closer to 100% offset — don't overproduce significantly. With a battery, export value decreases further since you can store and self-consume more.

What happens to my net metering credits at year-end? ▼

Most utilities do a "true-up" once a year. Any remaining credits typically expire or are paid out at a reduced rate. Some utilities pay them out at the avoided-cost rate; others forfeit them. Design your system so annual solar production roughly matches annual consumption to minimize wasted credits. A few utilities have monthly true-up (no annual carryover), which makes winter deficits more costly — check your utility's specific policy.

How does adding a battery affect net metering savings? ▼

With full net metering (retail credit rate), adding a battery doesn't improve economics much — you earn the same whether you store or export. With reduced net metering (export credit below retail), a battery lets you store daytime excess and use it in the evening instead of exporting at a lower rate. This self-consumption strategy is increasingly important in California (NEM 3.0), Nevada, and Hawaii. Battery payback without incentives is typically 8-12 years; with the federal tax credit (30%) and time-of-use rates, it can be 5-8 years.