Marketing & SaaS Calculators
ROAS, lifetime value, conversion rate and ad metrics.
A 4× ROAS on a 40% margin leaves $0.60 of profit per $1 of ad spend, not $3. These ten calculators cover the acquisition and retention metrics that decide whether marketing pays: ROAS, CAC, LTV, churn, MRR, conversion rate, CPC, CPM and CTR.
All 10 marketing & saas calculators
These metrics only mean something in pairs
Every number on this page is misleading alone, and that is the most useful thing to know about them. A low CPC is worthless if those clicks do not convert. A high ROAS can hide a loss once cost of goods is counted. A low CAC means nothing until you know what a customer is worth. Read them in pairs and the picture becomes honest.
Formula and benchmark for each metric
| Metric | Formula | Commonly cited target |
|---|---|---|
| ROAS | Revenue ÷ ad spend | Above break-even, which is 1 ÷ margin |
| CAC | Sales and marketing spend ÷ new customers | Judged only against LTV |
| LTV | Profit per customer over the relationship | About 3× CAC |
| CAC payback | CAC ÷ monthly gross profit | Under 12 months |
| Churn | Customers lost ÷ customers at start | Under 1% monthly for SMB |
| Conversion rate | Conversions ÷ visitors | Varies enormously by industry |
| CPC | Spend ÷ clicks | Only meaningful beside conversion rate |
Reach metrics describe the price, not the result
At the top of the funnel, CPM is the cost of a thousand impressions and CTR is the share of those impressions that become clicks. Together they produce your effective cost per click, and the arithmetic is worth seeing: a $2 CPM at 0.1% CTR costs $2.00 per click, while a $20 CPM at 3% CTR costs $0.67. The expensive impressions are three times cheaper per visitor. Cheap reach in front of the wrong audience is not a bargain, and judging a media buy on CPM alone is how it gets bought anyway.
Break-even ROAS is the number nobody calculates
The most common mistake in paid acquisition is treating ROAS as though it measured profit. It measures revenue. If your gross margin is 40%, every dollar of revenue leaves 40 cents before ad spend, so you need a ROAS of 1 ÷ 0.40 = 2.5× simply to break even. At a 4× ROAS you keep 60 cents per dollar spent, not three dollars. On a thin margin the break-even point rises fast: at 20% margin it is 5×.
Retention is the half that gets ignored
Acquisition metrics get the attention because they are what the ad platform reports back to you. Retention decides the outcome. Churn sets how long a customer stays, since average lifetime is roughly 1 ÷ churn and 5% monthly churn means about 20 months, and lifetime is what LTV is built from. Cutting churn raises LTV, which raises the CAC you can profitably afford, which opens channels that were previously too expensive. It works in the other direction too, which is how a business with strong acquisition numbers quietly stops growing.
Marketing & SaaS Calculators: common questions
What ROAS do I need to break even?
1 divided by your gross margin. At a 40% margin that is 2.5×, and at 20% it is 5×. ROAS measures revenue rather than profit, so a figure that looks healthy can still be a loss once cost of goods is counted.
What is a good LTV to CAC ratio?
Around 3:1 is the usual target. Below 1:1 you lose money on every customer. Far above 4:1 normally signals underspending rather than excellence, since you could profitably acquire more customers and are choosing not to.
Which marketing metric should I track first?
The pair of CAC and LTV, because every other number feeds one of them. CPC, CPM, CTR and conversion rate explain why CAC is what it is, and churn explains why LTV is what it is.
How long should CAC payback take?
Under 12 months is the common target and under 6 is excellent. Payback decides whether growth funds itself from cash flow or needs outside money, which is why two businesses with identical LTV:CAC ratios can be in very different positions.