LTV:CAC Ratio Calculator

What the LTV:CAC ratio calculator does

The LTV:CAC ratio calculator compares how much a customer is worth over their lifetime with how much it costs to acquire them, two central numbers for any subscription, SaaS, or repeat-purchase business. Dividing lifetime value (LTV) by customer acquisition cost (CAC) gives a ratio that shows whether your growth is making money or losing it. The tool returns the ratio alongside both inputs so you can check the numbers you entered.

Why the ratio matters

Every growing company spends money to win customers, and the ratio shows whether those customers eventually return more than they cost. Founders, investors, and marketing leaders all use it.

A ratio above 1 means customers are worth more than they cost to acquire. Breaking even is not enough, though: CAC is only part of the cost of running a business, which also carries product, support, overhead, and the cost of spending money up front and recovering it slowly. A 1:1 ratio is a warning sign.

The widely cited benchmark is 3:1. At that level each customer returns three times their acquisition cost over their lifetime, leaving enough margin to cover the rest of the business and still grow. It is a rule of thumb, but it has held up across enough companies to become the default target boards and investors expect.

Reading your result

• Below 1.0, you lose money on every customer you acquire, and growth cannot be scaled without fixing the underlying economics.
• Between 1.0 and 3.0, acquisition is profitable in principle but often too thin to sustain once overheads and payback timing are included; many companies in this band are effectively subsidising growth.
• Around 3.0 is the healthy benchmark: customers comfortably repay their acquisition cost with room to fund the rest of the business.
• At 5.0 and above, unit economics are strong, but often because of underinvestment. If each customer is this profitable, you can probably afford to spend more and grow faster.

The two inputs

Customer lifetime value (LTV) is the total profit you expect from a customer across the whole relationship, measured on gross margin, not raw revenue. A customer who pays a lot but is expensive to serve is worth less than the revenue suggests. Use margin, a realistic retention assumption, and any expansion revenue you can reliably count on.

Customer acquisition cost (CAC) is the fully loaded cost of winning a customer: advertising, sales salaries and commissions, marketing tools, agency fees, and content, divided by the number of new customers those efforts produced in the same period. Leaving out salaries or overhead is the most common mistake, and it flatters the ratio.

Be conservative with LTV and generous with CAC. If the ratio still looks healthy under cautious assumptions, you can rely on it.

Setting an acquisition budget

If you know your LTV and accept the 3:1 benchmark, the most you should pay to acquire a customer is roughly one third of LTV. A customer worth 1,200 in lifetime value supports an acquisition cost of up to about 400 while staying on target.

That ceiling applies to bid prices, sales compensation, and channel spend. When a marketing channel pushes CAC above it, pull back or improve conversion before adding budget.

Common mistakes

• Using revenue instead of margin for LTV, which overstates what a customer is worth.
• Excluding salaries from CAC. Sales and marketing headcount is usually the largest acquisition cost, and leaving it out can double the apparent ratio.
• Ignoring payback time. Two businesses can share the same ratio while one recovers its CAC in three months and the other in three years. The ratio measures eventual profitability, not cash flow timing, so pair it with a payback measure.
• Chasing an ever-higher ratio. Beyond the benchmark, a rising ratio often means you are underspending on growth, not becoming more efficient.

Testing scenarios

Raise your assumed retention and watch LTV and the ratio climb, or add the salaries you left out of CAC and see how much thinner the picture becomes. Track the ratio over time: one that improves as you scale shows a business getting stronger as it grows.

This article is general information only and is not financial or business advice.

About This LTV CAC Ratio Calculator

Use this LTV CAC ratio calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.