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Refrigerant Leak Rate Calculator

Turn a refrigerant top-off into an annualized leak rate with the EPA’s annualizing method, and see whether it is above the federal repair threshold for the appliance.

Method reviewed October 26, 2026. Version 1.0.0. How it works

Your inputs

Unit system

Pounds added this time (or several additions related to the same leak).

If refrigerant has not been added before, or it was more than a year ago, enter 365 or more: the method caps the period at 365 days.

Result

Above the repair threshold

Annualized leak rate
45.6%
Federal repair threshold
20%

45.6 % per year (above the repair threshold).

  • A leak rate above 20 % triggers the repair, verification and record-keeping requirements of 40 CFR 84.106. Check the regulation for the deadlines and exceptions that apply to your appliance.
  • The 40 CFR 84.106 repair threshold for commercial refrigeration is 20 %. This is a calculation aid, not a compliance determination; state and local rules may be stricter.
Refrigerant lost per year at this rate
45.6lb
Show the working
  1. Step 1: pounds added ÷ full charge
    15 ÷ 100 = 0.15
  2. Step 2: the shorter of the days since the last addition or 365, ÷ 365
    120 ÷ 365 = 0.3288
  3. Steps 3 and 4: Step 1 ÷ Step 2 × 100
    0.15 ÷ 0.3288 × 100 = 45.63 %

How the EPA leak rate is calculated

Each time refrigerant is added, the EPA rules ask what share of the full charge would be lost over a year at the current rate. The annualizing method has four steps:

  • Step 1: divide the pounds added to return the appliance to full charge by its full charge.
  • Step 2: take the number of days since refrigerant was last added — or 365, whichever is shorter — and divide by 365.
  • Step 3: divide the result of step 1 by the result of step 2.
  • Step 4: multiply by 100 to get a percentage.

So 15 lb added to a 100 lb system 120 days after the last addition is 0.15 ÷ (120 ÷ 365) × 100 = 45.6 % per year.

Which threshold applies

The federal repair thresholds are 20 % for commercial refrigeration, 30 % for industrial process refrigeration and 10 % for comfort cooling and other appliances. Which rule applies depends on the refrigerant:

  • HFCs and other high-GWP substitutes (such as R-410A, R-404A or R-134a): from January 1, 2026, appliances with a full charge of 15 lb or more fall under 40 CFR 84.106. Residential and light-commercial air conditioners and heat pumps are excluded.
  • Ozone-depleting refrigerants (class I and II, such as R-22): appliances with 50 lb or more fall under 40 CFR 82.157.

When the leak rate exceeds the threshold, the rules require the leak to be repaired within set deadlines, verified and recorded. The calculator flags the threshold; the regulation sets out the deadlines and exceptions.

Worked example

These are the example values the calculator opens with, and the result the engine calculates for them.

Inputs

Refrigerant added to return to full charge
15 lb
Full charge of the appliance
100 lb
Days since refrigerant was last added
120 days
Appliance type
Commercial refrigeration
Refrigerant
HFC or high-GWP substitute (e.g. R-410A, R-404A, R-134a)

Result

Annualized leak rate
45.6 %
Federal repair threshold
20 %
Refrigerant lost per year at this rate
45.6 lb

45.6 % per year (above the repair threshold).

Assumptions

  • Annualizing method from the EPA rules: (pounds added ÷ full charge) ÷ (the shorter of the days since the last addition or 365 ÷ 365) × 100.
  • Thresholds: 20 % commercial refrigeration, 30 % industrial process refrigeration, 10 % comfort cooling and other appliances — under 40 CFR 84.106 (from January 1, 2026; HFCs and substitutes with GWP above 53; 15 lb or more; residential and light-commercial AC and heat pumps excluded) or 40 CFR 82.157 (class I and II refrigerants; 50 lb or more).

Limitations

  • The rules also allow a rolling-average method; a facility must use the same method for all its appliances. This tool uses the annualizing method only.
  • Applicability depends on details this tool does not check, such as the refrigerant’s exact listing and the appliance’s end use. Read the regulation or ask a compliance professional before relying on the result.

Frequently asked questions

What if refrigerant was never added before?

Use 365 days. The method takes the shorter of the days since the last addition or 365, so any period of a year or more counts as 365 days.

Does this apply to my home air conditioner?

The HFC rule (40 CFR 84.106) excludes residential and light-commercial air conditioners and heat pumps, and most home systems hold far less than 15 lb. State rules can still apply, and only certified technicians may handle refrigerant.

Is there another way to calculate the leak rate?

Yes. The rules also allow a rolling-average method that looks at all additions over the past year. A facility has to use the same method for all its appliances. This calculator uses the annualizing method.

Sources

  1. 40 CFR 84.102 (definition of leak rate) and 84.106 (leak repair, from January 1, 2026) — U.S. EPA, Code of Federal Regulations (eCFR). Annualizing method: pounds added ÷ full charge, divided by (the shorter of days since the last addition or 365) ÷ 365, × 100. Repair thresholds for appliances of 15 lb or more containing HFCs or substitutes with GWP above 53: 20 % commercial refrigeration, 30 % industrial process refrigeration, 10 % comfort cooling and other appliances; residential and light-commercial AC and heat pumps excluded.
  2. 40 CFR 82.152 and 82.157 (ozone-depleting refrigerants) — U.S. EPA, Code of Federal Regulations (eCFR). Same annualizing method; since April 10, 2020 applies to appliances with 50 lb or more of class I or class II refrigerant (for example R-22): 20 % commercial refrigeration, 30 % industrial process refrigeration, 10 % comfort cooling and other appliances.

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