AMI percent calculator
Computes percent-of-AMI for a borrower in a specific county and family size, using FFIEC family-size adjustment factors.
From FFIEC 2025 county / metro AMI table.
1-8 person households (FFIEC range).
Gross annual; the field used in income-eligibility programs.
Percent of AMI
102.3%
Above moderate (≤120%)
Family-size adjusted median
$95,800
Family-size factor: ×1.00
How it works. The calculator multiplies the area median income by the FFIEC family-size factor (1-person 0.70, 4-person 1.00, 8- person 1.32) to get the adjusted median, then divides borrower income by adjusted median for percent-of-AMI.
Where to find AMI for your area. The FFIEC publishes AMI tables annually. RateStack's API exposes the same data via GET /v1/ami/lookup. For binding eligibility decisions, use the platform endpoint — it's versioned per year so historical replay produces the correct numbers.
Programs typically tier eligibility at 50% (very low), 80% (low), 100% (moderate), and 120% AMI. Specific overlays vary by investor and HFA.