DC:AC Ratio (Inverter Load Ratio) Calculator
Check the ratio of array DC capacity to inverter AC rating — the inverter load ratio — and see whether it sits in the typical range or risks clipping.
- The DC:AC ratio (inverter load ratio) divides the array's DC capacity by the inverter's AC rating.
- Modern systems are commonly oversized on the DC side — ratios around 1.1 to 1.4 — to use the inverter better across the day.
- Very high ratios increase clipping, when the array briefly produces more than the inverter can output, so the tool flags ratios worth a closer look.
DC:AC ratio
1.32
Assessment
A typical, healthy ratio — a modest DC oversize that uses the inverter well across the day, with little clipping.
The DC:AC ratio — also called the inverter load ratio (ILR) — is simply the array's DC capacity divided by the inverter's AC rating:
DC:AC = array (kWp) ÷ inverter (kW)
A ratio above 1.0 means the array is “oversized” relative to the inverter. Modest oversizing (commonly ~1.1–1.4) harvests more energy in the morning, evening and on cloudy days, when the array rarely reaches its nameplate. Push it too high and the inverter caps (“clips”) the array's peak on the brightest days. The right number depends on your panels, orientation, climate and goals — treat this as a sanity check, not a design.
Estimates only — for guidance, not a quote or engineering specification. Nothing you enter is stored or sent anywhere; the maths runs entirely in your browser.
Frequently asked
- Is this calculator free to use?
- Yes. The DC:AC ratio calculator is free and needs no sign-up. It runs entirely in your browser.
- Is my data stored or sent anywhere?
- No. The calculator runs in your browser and stores nothing. The figures you enter are not saved or sent anywhere.
- What DC:AC ratio is normal?
- Many residential systems sit around 1.1 to 1.4, with the best choice depending on your panels, orientation and goals. This is general guidance, not a design recommendation — confirm with your installer.
More tools
Sizing Tool
Solar System Size Calculator
Turn your daily energy use, sun hours and system losses into a recommended array size, panel count and inverter rating.
Financial Tool
Solar Payback Calculator
Estimate annual savings and payback period from system cost, generation, self-consumption, electricity rate and feed-in tariff.
Engineering Tool
Solar Panel Power Density Calculator
From rated power and module dimensions, compute power density in W/m², module efficiency and panels needed per kilowatt.