Refrigerant Leak Rate Calculator

EPA 40 CFR 84.106 · annualizing and rolling-average methods · runs in your browser, nothing is sent anywhere

Enter the appliance's full charge and each refrigerant addition. You get the leak rate, the threshold for your appliance type, and what to do next if you are over it.

This calculator is an informational aid, not legal advice. Verify against 40 CFR Part 84 Subpart C and EPA guidance (epa.gov/hfcs). Results depend on your inputs. Regulation text: eCFR 40 CFR 84.106.

How the leak rate is calculated

Annualizing: rate = (pounds added to return the appliance to full charge, in one or several additions for the same leak ÷ full charge) × (365 ÷ the shorter of 365 and the days since the last addition) × 100.

Rolling average: rate = (pounds added in the last 365 days ÷ full charge) × 100. If fewer than 365 days have passed since the last successful follow-up verification test, that shorter period is used, with no scaling to a full year (definition of “leak rate”, 40 CFR 84.102). For the first calculation after January 1, 2026 the rule substitutes 365 days (annualizing) or the pounds added since January 1, 2026 (rolling average) (84.106(b)(1)–(2)).

You calculate the rate each time refrigerant is added, except after a retrofit, after installing a new appliance, or for a qualifying seasonal variance. A rate over the threshold starts the repair clock. After a repair, the rate must come out below the threshold (84.106(d)(2)); a result equal to the threshold does not confirm the repair.

Frequently asked questions

Which leak rate method should I use: annualizing or rolling average?

Both are allowed by 40 CFR 84.106. Annualizing scales the refrigerant added at one service event to a full year using the days since the previous addition. The rolling average adds up everything added over the past 365 days. Pick one method and use it for every appliance at a facility; do not mix methods within a facility.

Which appliances are covered?

Appliances with a full charge of 15 lb or more that use an HFC or substitute with a GWP above 53. Residential and light commercial air conditioning and heat pump appliances are an exempt subsector, but the rule does not define the boundary of that subsector precisely, so check EPA guidance if your equipment is close to the line. A multi-circuit appliance is evaluated per independent circuit.

What are the leak rate thresholds?

Commercial refrigeration 20%, industrial process refrigeration 30%, and comfort cooling and other appliances 10%. A rate above the threshold triggers repair, verification testing and recordkeeping duties.

What happens when the rate is above the threshold?

Repairs are due within 30 days of adding the refrigerant (120 days if an industrial process shutdown is required). An initial verification test is run after the repair, and a follow-up verification test within 10 days of the successful initial test, or within 10 days of the appliance returning to normal operating conditions if it was evacuated.

How do I calculate the refrigerant leak rate?

Annualizing method: pounds added divided by the full charge, multiplied by 365 divided by the days since refrigerant was last added, as a percentage. Rolling average method: pounds added over the past 365 days divided by the full charge, as a percentage. The calculator above does both from the additions you enter.

When must the leak rate be calculated?

Each time refrigerant is added to an appliance that is covered by the rule, with the exceptions listed below for retrofits, new installations and qualifying seasonal variances. Compare the result with the threshold for the appliance type to see whether repair duties apply.

What is an acceptable refrigerant leak rate?

The rule sets trigger rates rather than an acceptable level: 20% for commercial refrigeration, 30% for industrial process refrigeration, and 10% for comfort cooling and other appliances. Below the trigger rate no repair deadline starts, but refrigerant additions still have to be recorded.

Does the AIM Act 15-pound rule apply to my system?

It applies if the appliance has a full charge of 15 lb or more of an HFC or substitute with a GWP above 53 and is not in the exempt residential or light commercial air conditioning and heat pump subsector. Check each independent circuit separately, and confirm borderline cases with EPA guidance.

Does this calculator save my refrigerant log?

No. It runs in your browser and nothing is stored or sent. Keep your own service records, calculations and verification test results for the retention period above; you can print the result from the calculator.

Which additions can I leave out of the calculation?

The rule says to calculate the leak rate each time refrigerant is added, except after a retrofit, after installing a new appliance, or for a qualifying seasonal variance. Tick "does not count" on those rows.

Which records do I need to keep?

Keep service and refrigerant-addition records, leak rate calculations and verification test results for at least three years. Records for an appliance are kept until three years after it is retired. Appliances that lose 125% or more of their full charge in a calendar year are reported to EPA by March 1 of the next year.