Tool · Investor Sam Biz

Customer Lifetime Value (LTV) Calculator

June 30, 2026 • By the Investor Sam Editorial Team • Reviewed by Berly Sam Varghese, Editor
Lifetime value, or LTV, is the total gross profit you expect from a customer across their entire relationship with you. For any subscription or recurring-revenue business it is the number that determines how much you can afford to spend to acquire customers. This calculator combines average monthly revenue, gross margin, and monthly churn to estimate LTV and the average customer lifespan. A lower churn rate stretches the lifespan and lifts LTV dramatically.

Example: Average revenue per customer / month: 50 $ · Gross margin: 80 % · Monthly churn rate: 5 %

Lifetime value (gross profit)$800
Average customer lifespan20
Lifetime revenue$1,000

Worked example

A customer paying $50 a month at an 80% gross margin who churns at 5% a month lives, on average, 1 divided by 0.05 = 20 months. Over that time they generate $50 x 20 = $1,000 of revenue, and at 80% margin the lifetime value is $800 of gross profit. Cut churn to 2.5% and the average lifespan doubles to 40 months, pushing LTV to $1,600 from the exact same customer.

Frequently asked questions

Why use gross margin instead of revenue?

Because revenue is not profit. LTV should reflect the profit a customer contributes, so we multiply their lifetime revenue by your gross margin. Comparing a margin-based LTV to acquisition cost gives a true picture of profitability.

How does churn drive lifespan?

Average lifespan is one divided by the monthly churn rate. A 5% churn means an average of 20 months; a 2% churn means 50 months. Small reductions in churn produce large gains in LTV, which is why retention is so valuable.

What churn rate should I use?

Use your actual measured monthly churn: customers lost in a month divided by customers at the start of the month. If you do not have it yet, model a range to see how sensitive your LTV is to retention.

How do I use LTV?

Compare it to your customer acquisition cost. A healthy business keeps LTV at least three times CAC and recovers CAC within about a year. Our LTV:CAC ratio tool makes that comparison directly.

💎
InvestorSam.com
Stock analysis, market insights & portfolio research — free
Ready to put these numbers to work?
Get stock picks, earnings analysis, and market commentary from Investor Sam.
Visit InvestorSam.com →

Sources

Berly Sam Varghese · Editor, Investor Sam

Berly Sam Varghese is an engineer who treats money the way he treats any hard problem — something to be engineered, not gambled on. He funded years of education and built real financial stability the patient way, by living below his means and investing rather than borrowing. He writes for the person building something and trying to keep the finances sane. He reviews and approves every article on Investor Sam and checks the figures against primary sources before anything is published. More about our standards.