The MRR-to-Goal Calculator

The number most founders never work out

Everyone knows their MRR and their target. Almost nobody knows the third number, which is the one that decides whether the target is even available at the current rate.

It works like this. Churn takes a percentage of the base every month, and a percentage of a bigger base is a bigger number. At €2,000 MRR, 4% churn costs you €80. At €10,000 it costs €400. So the euros you lose grow while the euros you add stay flat, and eventually the two meet. That meeting point is the plateau, and with no expansion revenue in the mix it is simply new MRR divided by your monthly churn rate.

Fifteen customers a month at €45 is €675 of new MRR. Against 4% churn that lands at €16,875, because 675 divided by 0.04 is 16,875. The calculator above shows a slightly higher figure for the same inputs because it also carries 1% monthly expansion, which slows the decay. Either way, that is where the line goes flat, and it goes flat whether you like the number or not.

This is why so many small SaaS businesses stall between €3,000 and €8,000 and then blame motivation. The founder did not get lazy. The arithmetic ran out. The customer maths behind €10k MRR walks the same numbers with the customer counts written out.

How the maths works

Each month the model does three things in that order. It takes churn off the existing base. It applies expansion to whoever stayed. Then it adds the customers you signed that month, multiplied by your average price. Repeat sixty times and you have the projection table.

That is one line of arithmetic run over and over, and it beats intuition every time for a dull reason. Intuition adds. The model multiplies. Nobody guesses compound decay well, which is why a founder can be genuinely surprised in month fourteen by a number that was decided in month one.

The projection stops at 24 months because two years is roughly the horizon a solo founder can plan against without inventing things. If the target has not arrived by then, the interesting question is not "how many more months" but "which of the three inputs is wrong". The €10k MRR breakdown runs the same model at three different price points, which is the fastest way to see how much of this is decided by what you charge.

Three levers, and one of them is nearly free

Acquisition. Doubling new customers a month doubles the ceiling. It is the most obvious lever and the most expensive one, because it is a bill you pay again every month for the rest of the business. It also does not happen by wishing. Put your real reply and close rates through the outreach volume estimator and see what doubling actually costs you in conversations per morning.

Price. Average revenue per customer sits in exactly the same multiplication as volume, so €45 to €60 moves the ceiling as hard as 15 customers a month to 20, without one extra email. The honest catch is that a higher price usually lowers conversion, so the two changes partly cancel. Worth testing before it is worth assuming.

Churn. This is the cheap one, and it is cheap because it divides rather than multiplies. Halving churn doubles the plateau. Going from 6% to 3% has the same effect on your ceiling as doubling every distribution activity you do, and unlike acquisition it is mostly a fixed piece of work: better onboarding, an email in week one, a reason to come back on day thirty. You do it once and the ceiling stays moved.

The order most founders work in is acquisition, then price, then churn. The order the arithmetic suggests is close to the reverse.

What to do once you have the number

Take the customers-a-month figure and stop treating it as an outcome. It is an input to something you can put in a calendar. The 100 in 100 days calculator turns a customer target into a number you have to hit on every working day, and that daily number is the only part of this you can actually act on tomorrow morning.

Then pick where those customers come from. There are four ways: reach out to people who already know you, post something in public where strangers find it, reach out to strangers, or pay to get in front of people. Alex Hormozi calls that set the Core 4. The guide to the Core 4 covers what each one costs, the ranked channel breakdown compares them for indie SaaS specifically, and the marketing channel quiz will pick one for you if the deciding is the part that keeps stalling.

If the required rate comes back at four or five times what you are doing now, that is information rather than a verdict. Lower the target, extend the window, raise the price, or go after the churn. The first 100 customers playbook and the €10k MRR customer maths both take the same numbers and turn them into a week of work.

Where to get honest inputs

Churn comes from your billing dashboard, counted as cancellations divided by customers at the start of the month. Average revenue per customer comes from MRR divided by paying customers, today, not from your pricing page. New customers a month is the average of the last three months, including the bad one.

If you have fewer than three months of data, the numbers here are a sketch and you should treat them as one. Run the real thing for a quarter and come back. A calculator fed with hope produces a plan built on hope, and that plan usually falls over in the exact month this table says it will.