Match the period
Use inputs from the same month, quarter, or year. Do not divide annual acquisition spend by one month of new customers or mix monthly churn with annual revenue.
Free SaaS calculators
SaaS calculators for recurring revenue
Use these free, ungated SaaS calculators to measure revenue retention, customer churn, monthly recurring revenue movement, and customer acquisition economics. Each tool shows the formula, inputs, worked example, and limits behind the result.
NRR and GRR calculator
Net revenue retention measures how recurring revenue from the starting customer base changed after expansion, contraction, and churn. Gross revenue retention uses the same base but excludes expansion. New-customer revenue is excluded from both metrics.
Open calculator 02Churn and retention calculator
Customer retention rate is the share of starting customers still active at the end of a period. Revenue churn measures recurring revenue lost through cancellation and contraction. Use separate customer and revenue views so acquisition or expansion cannot hide the underlying loss.
Open calculator 03MRR and ARR calculator
Ending monthly recurring revenue equals starting MRR plus new, expansion, and reactivation MRR, minus contraction and churn MRR. Multiply ending MRR by 12 to calculate the corresponding annual recurring revenue run rate.
Open calculator 04SaaS LTV:CAC and payback calculator
This calculator estimates customer lifetime value from monthly average revenue per account, gross margin, and monthly customer churn. It divides matched sales and marketing spend by new paying customers for CAC, then compares LTV with CAC and estimates payback months.
Open calculatorKeep the population consistent
Compare the same customer segment, product, currency, and recurring-revenue policy across every input.
Name the policy
Document how you treat reactivation, pauses, usage charges, credits, and customer migrations so the metric can be reproduced.
Inspect the movements
A blended result reports what happened. Review the customers, upgrades, downgrades, cancellations, and acquisition cohorts underneath it before choosing an action.
A clean formula still needs a clean reporting policy
A useful SaaS metric should be reproducible. The reporting period, customer population, revenue policy, and formula need to stay the same from one review to the next.
These calculators make that math visible. They help founders, finance, RevOps, and customer teams check a number before tracing it back to the accounts and movements that produced it.
Start with the calculator that matches the decision in front of you. Use NRR and GRR for the existing revenue base, churn and retention for customer loss, MRR and ARR for the full recurring-revenue bridge, and LTV:CAC for acquisition economics.
Before you put the result in a board deck
Are the Prevenue SaaS calculators free?
Yes. The calculators are free to use and do not require an email address. The formula, worked example, and calculation limits are visible on each page.
Which SaaS calculator should I use first?
Use the NRR calculator for existing-customer revenue, the churn calculator for customer counts, the MRR calculator for a complete recurring-revenue bridge, and the LTV:CAC calculator for acquisition economics.
Can these results replace finance or billing reports?
No. They are transparent planning and validation tools. Reconcile the result with your billing system, finance policy, cohort definitions, and accounting records before using it in formal reporting.
The calculation is the check. The customer movement is the clue.
A blended metric can tell you where to look. It cannot tell you which account changed, why it changed, or who should act next. That is where billing, product, support, lifecycle, and account evidence have to meet.
See the evidence behind the metric
Know which accounts need a Grow, Save, Convert, or Watch decision.
Prevenue connects supported billing, product, and account evidence, then routes reviewable revenue signals while your team keeps control.