Kairos Microtools

Subscription Churn Revenue Calculator

See what churn really costs your SaaS — and what fixing it is worth. Free, no signup.

Early-stage Growth Mature

Current MRR (USD)

Paying Customers

Monthly Churn Rate (%)

Target Churn Rate (%)

CAC per Customer (USD, optional)

Currency label

Monthly Revenue Lost

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Customers Lost / Month

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Net Revenue Retention (12mo)

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MRR after 12mo (zero new sales)

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New Customers / Mo just to hold flat

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Annual Revenue Saved at Target

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Why track churn revenue

Churn is a leak, not a cost. It compounds monthly — 5% looks small until you see the 12-month hole.

Fixing beats buying. Retaining a customer is usually cheaper than replacing one via ads.

No spreadsheet. Enter MRR and churn; see the real number in one view.

The free calculator shows one scenario. Pro unlocks the full picture:

12-month forecast spreadsheet — churn modelled at 2% / 5% / 8% / 12% side by side
12 retention playbooks (PDF) — onboarding, billing nudges, win-back sequences
"Fix churn" vs "buy ads" ROI — what retaining costs against replacing through ads
Retention tracker — log each initiative and the MRR it actually saved
Works in Excel, Numbers and Sheets — no login, nothing leaves your machine

$19 — instant Excel + PDF download, yours forever

Free calculator stays free. No subscription, no login. Checkout on Gumroad.

Is this free?

Yes — the single-scenario calculator is free and needs no signup. Pro is a one-time $19 upgrade.

Does it predict my revenue?

No. It does the math from the numbers you enter. It is not financial advice.

Who is it for?

SaaS and subscription founders who want to quantify churn's revenue impact without a BI tool.

What does Pro add?

An Excel toolkit — a 12-month forecast at four churn rates, a fix-vs-buy ROI comparison, and a retention tracker — plus a 12-playbook PDF.