LTV:CAC Ratio Calculator
If a venture investor could keep only one metric about your business, it would probably be this one. The LTV to CAC ratio compresses retention, pricing, margin, and acquisition into a single read on whether your growth compounds — enter two numbers and see where you land.
The LTV:CAC ratio is customer lifetime value ÷ customer acquisition cost, and it tells you how many dollars of value each dollar of acquisition buys back. The benchmark that traveled out of David Skok’s SaaS work and into nearly every board deck: roughly 3:1 to 5:1 signals healthy, repeatable economics. Below 1:1 you destroy value on every customer; far above 5:1 you are usually starving a profitable engine. For an honest figure, divide gross-profit LTV by CAC, not revenue LTV.
LTV:CAC Ratio Calculator inputs and result
| Ratio | What it means |
|---|
How to use this calculator
- Enter lifetime value, gross-profit if possibleThe cleanest ratio uses the gross profit a customer throws off over their life, not their revenue. If your LTV already nets out cost of goods, leave the margin field at zero.
- Convert revenue LTV with the margin fieldIf the only LTV you have is revenue-based, set your gross margin and the tool discounts it to a gross-profit figure before computing the ratio — otherwise the result flatters you.
- Enter fully-loaded CACUse acquisition cost that includes media, people, tools, and agencies. A CAC that counts ad spend only inflates the ratio and hides the real economics.
- Read the ratio against the bandsBelow 1 you lose value per customer, 3 to 5 is the healthy zone, and above 5 usually means you are leaving growth unfunded. The verdict and table place you instantly.
- Export the readCopy a share link, download the CSV for your model, or print a one-pager for the investor update or the budget review.
RGM Expert Says
We treat this ratio as a diagnosis, not a grade. When it comes back thin, the instinct is to attack CAC — cheaper clicks, better targeting — but more often the real lever is the numerator. A business stuck at 2:1 with a six-month-lived customer does not have a media problem; it has a retention problem wearing a media costume. Reading LTV and CAC together points you at the cause instead of the symptom.
The gross-profit detail is where most do-it-yourself ratios go wrong. Teams divide revenue LTV by CAC, land on a comfortable 5:1, and plan as if the economics are bulletproof — then discover that on a 40% margin the honest figure was 2:1. We force the margin adjustment in every model we build, because a ratio computed on revenue is not measuring whether the business makes money, only whether it makes sales.
The reading we enjoy delivering least is the suspiciously good one. A ratio north of 7:1 almost never means a client has cracked growth; it means they are too timid with spend and a competitor with worse economics but more nerve is taking the market. We use that number to argue for a higher allowable CAC — spend more, accept a healthier 3-to-5 ratio, and own more of the category while the math still works.
How it works
The ratio sets the lifetime worth of a customer against the cost of acquiring one, so every input that shapes value or cost flows into a single comparison.
- Lifetime value — total worth of a customer over their life; use gross profit for honesty.
- CAC — fully-loaded cost to acquire one customer: media, people, tools, agencies.
- Gross margin — optional; converts revenue LTV into gross-profit LTV before the ratio.
Worked example: $1,200 LTV ÷ $300 CAC = 4.0 : 1, a healthy ratio. If that $1,200 were revenue at a 50% margin, gross-profit LTV is $600 and the honest ratio is 2.0 : 1. The 3:1 rule traces to David Skok’s SaaS Metrics 2.0.
Why one ratio carries so much weight
The LTV:CAC ratio earned its place in every board deck because it folds four separate disciplines into one number. Retention and churn set how long a customer pays; pricing and margin set how much that is worth; targeting and conversion set what they cost to win. Move any one and the ratio moves, which makes it both a scorecard and a map — the figure tells you the score, and the inputs tell you which department holds the next gain.
The 3:1 anchor that practitioners quote comes from David Skok’s SaaS Metrics work, paired with a payback period under a year. Treat it as a center of gravity rather than a law: a 2.5:1 ratio with three-month payback can be healthier than a 4:1 with a two-year wait, because the faster business recycles cash and compounds sooner. The ratio is necessary, but read it alongside payback before you celebrate or panic.
Its most counterintuitive lesson is that a very high ratio is usually a warning, not a win. A 6:1 or 7:1 reading typically means a company is under-investing — protecting a beautiful ratio while a bolder rival floods the channel and takes share. The disciplined response is to spend the ratio down into the healthy band, accepting a higher CAC to capture a market that will not wait. Our CAC and LTV calculators feed the two inputs this read depends on.
Reading the LTV:CAC bands
The ratio travels across industries in a way raw CAC never can, because it is dimensionless. These bands are the widely used center of gravity, not hard cutoffs.
| LTV : CAC | Interpretation | What to do |
|---|---|---|
| Below 1 : 1 | Value-destroying | Stop scaling; fix LTV and CAC |
| 1 : 1 to 3 : 1 | Fragile, thin cushion | Deepen retention or efficiency |
| 3 : 1 to 5 : 1 | Healthy, repeatable | Scale with confidence |
| Above 5 : 1 | Under-investing | Spend more to take share |
What operators say about LTV:CAC
Aim for an LTV to CAC ratio of about 3:1 with payback under a year; far higher usually means you are not investing enough in growth.
The companies that win durably treat lifetime value as a product problem, not just an acquisition one — they make the customer worth more, not only cheaper to get.