# The Cost of Donor Attrition

A lapsed donor takes future gifts with them. That loss carries a number you can put in dollars.

## Key takeaways
- Donor attrition costs you twice: the future gifts a lapsed donor would have given, plus the money you already spent to acquire them.
- Nearly 70% of new donors give only once, so most attrition happens at the very start of the relationship, before a donor ever repays what they cost (Bloomerang).
- Overall donor retention was 43.3% in 2025, so a typical file loses more than half its donors each year, and every one carries foregone lifetime revenue (Fundraising Effectiveness Project).
- The annual bleed is measurable: donors lost multiplied by their average giving is current revenue walking out the door, before you count the future gifts that leave with them.
- Donor Insights reads your own giving records to show how many donors you are losing, what their giving was worth, and where the bleed is concentrated, so attrition stops being invisible.

When a donor lapses, you do not just lose this year's gift. You lose every gift they would have given, plus the money you already spent to bring them in. That is the cost of donor attrition, and it is larger than it looks because it runs into the future. With overall donor retention at 43.3% in 2025, according to the [Fundraising Effectiveness Project](https://publications.fepreports.org/archive/2025-q4/), a typical file loses more than half its donors each year, and each departure carries a price you can put in dollars.

## What does donor attrition actually cost?

Two things at once. First, the foregone lifetime revenue: the second, third, and tenth gifts a retained donor would have made, all of which stop the moment they lapse. Second, the sunk acquisition cost: what you paid in advertising, mail, and staff time to win that donor, which only pays back if they keep giving. A donor who lapses after one gift takes both with them, the future they would have funded and the cost of acquiring them, and leaves you to buy a replacement at a price that is usually higher than keeping them would have been.

This is why attrition is a spending line even though no invoice arrives for it. The dollars leave quietly, one lapsed donor at a time, and never show up as a cost on any report. Reading acquisition through [donor acquisition cost](https://donorinsights.com/articles/donor-acquisition-cost) tells you what a new donor costs to win; attrition tells you what it costs to lose one.

## How big is the bleed?

Bigger than most organizations admit, because most of it happens at the very start. Nearly 70% of new donors give only once, so the majority of the donors you acquire lapse before the relationship has a chance to pay back (Bloomerang). That matches the sector's first-time donor retention of 18.9% in 2025: roughly four in five first-time donors never give again. Attrition is not a slow trickle spread evenly across a loyal file. It is concentrated in the newest, most fragile donors, the exact people you spent the most to acquire.

**70%** — of new donors give only once, so most attrition strikes the donors you just paid to acquire ([Bloomerang](https://bloomerang.com/blog/donor-retention/))

## What is a lapsed donor's foregone lifetime value?

It is the giving they would have done if they had stayed. Picture a fictional organization, Ridgeway Aid, with a donor who gives $75 a year. The numbers below are illustrative. If that donor would have stayed five more years, their foregone lifetime value is $375, and if Ridgeway paid $40 to acquire them, the lapse turns that $40 into a pure loss on top of the $375 that never arrives.

The foregone value of one lapsed donor (hypothetical figures for a fictional org)

| Line | Amount |
| --- | --- |
| Annual gift | $75 |
| Years the donor would have stayed | 5 |
| Foregone future giving | $375 |
| Sunk acquisition cost now wasted | $40 |
| Total cost of this one lapse | $415 |

One donor at $75 a year does not feel like a $415 loss in the moment they slip away, which is precisely why attrition is underpriced. Multiply that across a file and the number gets serious fast. To put a defensible figure on the future giving that lapses, work from your own [donor lifetime value](https://donorinsights.com/articles/donor-lifetime-value) rather than a sector average, since what a retained donor is worth is specific to your file.

## What does a low retention rate cost per year?

You can size the current-year bleed directly: donors lost, multiplied by their average giving, is revenue walking out the door before you even count the future gifts that leave with them. Stay with an illustrative file of 5,000 donors giving $75 a year on average. At a 45% retention rate, 2,750 donors lapse in a year, and the giving that leaves with them is about $206,000, roughly the same again in current revenue that the organization must now raise just to stand still.

**$206,000** — current-year giving lost to lapse on an illustrative 5,000-donor file at 45% retention, before counting foregone future gifts

That figure is only the current year. The foregone future giving from those 2,750 donors sits on top of it, and next year the file starts the climb over again from a lower base. A few points of retention change the bleed sharply: keep even 5% more of those donors and the giving that walks out falls by roughly a fifth. Your [donor retention rate](https://donorinsights.com/articles/donor-retention-rate) is the dial that sets the size of this loss.

## Why is attrition more expensive than it looks?

Because you pay for it twice. First you lose the lapsed donor's future giving. Then, to hold the file steady, you have to acquire a replacement, and acquiring a new donor costs more than keeping an existing one, so every lapse quietly raises your total fundraising cost. A file that leaks donors is a file that must spend harder on acquisition every year just to avoid shrinking, which is the leaky-bucket trap in dollar terms.

> Increasing customer retention rates by 5% increases profits by 25% to 95%. — Harvard Business Review, citing Bain & Company (a for-profit finding, applied to fundraising by analogy)

Donors are not customers, and the parallel is imperfect, but the arithmetic of attrition runs the same way: small changes in how many donors you keep move the money more than almost anything you can do to acquisition. Spending to lower attrition is usually cheaper than spending to replace it.

## How do you stop the bleed?

Treat attrition as a number you manage, not weather you endure. In order:

1. Measure it: track how many donors you lose each year and what their giving was worth, so the cost stops being invisible.
2. Protect the first-time cohort, where most attrition happens, by thanking new donors fast and giving them a reason to give a second time.
3. Win back the winnable early, while a lapsed donor still remembers you, using the tactics in our guide to [lapsed-donor reactivation](https://donorinsights.com/articles/lapsed-donor-reactivation).
4. Watch the whole file's health with a regular [donor file health check](https://donorinsights.com/articles/donor-file-health), so a rising bleed is visible while you can still act on it.

That accounting is hard to keep by hand, because it means tying each lapsed donor to what their giving was worth and where the loss concentrates. Donor Insights reads your own giving records and shows how many donors you are losing, what they gave, and which cohorts are bleeding fastest, so attrition becomes a number you can see and act on rather than a quiet drain on every year's total.

## FAQ

**What is the cost of donor attrition?**

It is the future giving a lapsed donor would have made, plus the money you already spent to acquire them. Both are lost when a donor stops giving, and because the future giving stretches over years, the true cost is far larger than the single gift you see disappear.

**How do you calculate the cost of losing a donor?**

Take the donor's annual giving times the number of years they would have stayed to get foregone future value, then add the sunk acquisition cost. On an illustrative $75-a-year donor who would have stayed five years and cost $40 to acquire, the total cost of one lapse is about $415.

**Why is donor attrition so expensive?**

Because you pay twice: you lose the lapsed donor's future gifts, and you must acquire a replacement to stand still, which costs more than keeping the donor would have. Nearly 70% of new donors give only once (Bloomerang), so much of that expense hits the donors you most recently paid to win.

**How much does a low retention rate cost per year?**

The current-year bleed is donors lost times their average giving. On an illustrative 5,000-donor file at 45% retention, about 2,750 donors lapse and roughly $206,000 in current giving walks out, before any foregone future gifts. Keeping 5% more donors cuts that loss by roughly a fifth.

## Sources
- [Fundraising Effectiveness Project, Q4 2025 report (2025 data)](https://publications.fepreports.org/archive/2025-q4/)
- [Bloomerang, A Guide to Donor Retention (share of new donors who give only once)](https://bloomerang.com/blog/donor-retention/)
- [NonProfitPRO, Giving Grows as Donor Decline Continues in 2025 (FEP coverage)](https://www.nonprofitpro.com/article/fundraising-growth-in-2025-continues-to-mask-a-shrinking-donor-base/)
- [Harvard Business Review, The Value of Keeping the Right Customers (Bain & Company)](https://hbr.org/2014/10/the-value-of-keeping-the-right-customers)

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Source: DonorInsights.com — https://donorinsights.com/articles/donor-attrition-cost