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Donor Retention & Attrition Calculator

Calculate donor retention rate, attrition, new-donor and repeat-donor retention, the revenue lost to lapsed donors, how many new donors are needed just to stand still, and the value of lifting retention by a few points — with Fundraising Effectiveness Project benchmarks.

Donors who gave last year

Of those, how many gave again this year

Of last year's donors, how many were first-time donors

First-time donors from last year who gave again

New donors acquired this year

Average annual gift per donor

Cost to acquire one new donor

Retention improvement to model

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How it works

Retention = donors who gave in both years ÷ donors who gave last year; attrition = 1 − retention; revenue lost = lapsed × average gift; value of a lift = last-year donors × points × average gift

The single most important number in a fundraising programme is the share of last year's donors who give again: sector-wide it hovers around 40–45%, and for first-time donors only one in four or five returns, so most organisations pour new donors into a bucket that leaks faster than they can fill it. Retention is cheaper than acquisition — a lapsed donor cost money to recruit and a retained one gives more each year — which is why a five-point improvement is usually worth more than the entire acquisition budget it replaces. Tracking the rate by segment (first-time versus repeat, by channel, by gift size) shows where the leak is, and the fixes are mostly stewardship: fast thanks, impact reporting and a timely second ask.

Worked example

Of 1,200 donors last year, 540 gave again — 45% retention — but only 110 of the 500 first-time donors (22%) against 430 of 700 repeat donors (61%). The 660 lapsed donors took about $122,000 of giving with them; 620 new donors costing $59,000 produced a net loss of 40 donors. Lifting retention five points would keep 60 more donors, worth $11,100 a year — the same as $5,700 of acquisition.

Frequently asked questions

How do I count donors who skip a year?

Standard retention compares consecutive years; a donor returning after a gap is "reactivated", counted as recaptured rather than retained. Track reactivation separately — it is often the cheapest growth.

What retention should monthly donors have?

80–90% annually. Converting one-time donors to monthly giving is the most reliable way to move overall retention; sustainers also give 40–50% more over a year.

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Nonprofit metrics use the conventions of the Fundraising Effectiveness Project, Charity Navigator/BBB standards and US federal grant rules (2 CFR 200) in simplified form; benchmark ranges are sector-wide averages. Your auditor, board and funders' definitions govern reported figures.