Free tool · SaaS acquisition budget calculator

Can your unit economics pay for your growth target?

Enter your revenue per customer, your growth target and your funnel. You get two numbers: the most you can afford to spend on ads, and what hitting the target will actually cost. If they don't match, you'll see exactly what has to change.

01 Your unit economics

This sets the ceiling: the most a new customer is worth paying for.

On annual contracts? Divide the annual value by 12.

Revenue left after hosting, support and other delivery costs. Blank = 80%, typical for SaaS.

How long customers stay
Target LTV:CAC ratio

3:1 is the usual health line. Higher means more efficient but slower growth.

If your CAC target also has to cover sales salaries and tools, enter the part that's ad spend (often 40–60% for sales-led SaaS). Blank = 100%.

02 Your growth target
03 Your funnel

This sets what the target will really cost. Use your own numbers if you have them. Not sure about cost per lead? Estimate it with the Ad Budget Calculator.

Blank = 30% and 20%, common starting points for B2B SaaS. Your own numbers will make this far more accurate.

04 Budget (optional)

Extra budget to test keywords, audiences and creative. Blank = 20%.

Method

How the calculator works

Most budget calculators give you one number. This one gives you two, because "what can we afford?" and "what will it cost?" are different questions, and most SaaS budget problems come from mixing them up.

  1. LTV. Revenue per customer × gross margin × lifetime in months (or ÷ monthly churn). Gross margin matters: revenue you spend on delivering the product can't pay for acquisition.
  2. Affordable ceiling. LTV ÷ your target ratio gives the most you can pay for a customer. Multiply by the share that's ad spend and by your customer target to get the most you can spend on ads per month.
  3. Required budget. Cost per lead ÷ your lead-to-customer rate gives what a customer really costs in ad spend. Multiply by your customer target.
  4. Reality check. If the required budget is under the ceiling, the target works. If not, the calculator shows which lever has to move, and by how much: cost per lead, funnel conversion, revenue per customer or the ratio you accept.

The thinking behind this is in How to Set Your SaaS Paid Acquisition Budget.

Questions

SaaS acquisition budgets, answered

What's a good LTV:CAC ratio for SaaS?

3:1 is the common health line: each customer brings in three times what it cost to win them. Much higher than that, like 6:1 or more, often means you're under-investing and growing slower than you could. Below 3:1, acquisition is eating too much of the value.

Why use gross margin instead of revenue?

Because part of every euro of revenue goes to hosting, support and onboarding. Only the gross profit is left to pay back what you spent acquiring the customer. Using revenue makes CAC look more affordable than it is.

What's the difference between CAC and ad spend per customer?

Fully loaded CAC includes sales and marketing salaries, tools and agency fees, not just ad spend. If your CAC target has to cover all of that, only part of it is available for ads. That's what the "share of CAC that's ad spend" field is for.

How is this different from the Ad Budget Calculator?

The Ad Budget Calculator works up from platform benchmarks: what Google, LinkedIn or Meta typically cost for your industry. This one works down from your business: what a customer is worth and whether your funnel can deliver them at that price. Use the first to estimate cost per lead, then bring that number here.

The target doesn't work. What now?

Usually the fastest lever isn't cost per lead, it's lead quality. If the ad platforms optimise toward leads that never qualify, your lead-to-customer rate stays low whatever you spend. Feeding CRM lead quality back to the platforms is how you move it. On one account I manage, the qualified-to-lead rate went from about 31% to about 56%. Read the case study.