Free tool — Forecast Simulator
Your financial model is wrong. Find out how wrong.
Build a revenue model out of connected nodes, give every input a range instead of a number, and run it 10,000 times. You get probabilities you can plan against - not one confident line that misses.
No signup. Nothing to install. Runs in your browser.
You survive to month 24 in 84% of runs
10,000 runs · P10–P90
M24 MRR (P50)
€72K
Survives to M24
84%
Bankruptcy risk
16%
Biggest lever
Churn
01 — The problem
A spreadsheet forecast is a guess with better posture.
You picked 5% monthly growth because it looked reasonable. Every cell downstream inherited that decision, and the model now reports it back to you as a finding. Nobody in the room can see which numbers were known and which were typed.
One number
A point forecast has no error bars, so a plan built on it has no contingency either.
Standard spreadsheet practice
42%
of startups fail building something nobody wants — the demand assumption was never tested.
CB Insights
Compounding
A 2% error in month one is a 27% error by month twelve. Optimism compounds exactly like interest.
Arithmetic
02 — How it works
Four steps to a range, not a number.
Setup takes about five minutes. Most of it is us pre-filling benchmarks for you to argue with.
Step 1
Pick your revenue model
Eight to choose from — SaaS, marketplace, usage-based, transactional and the rest. We generate the right nodes and wire the loops for that shape.
Step 2
Argue with the benchmarks
Every parameter arrives pre-filled from your archetype, as a low and a high. Overwrite anything you actually know. Leave the rest.
Step 3
Run it 10,000 times
Each run samples every range independently, month by month. Cash hitting zero ends that run — no imaginary credit line.
Step 4
Read the probabilities
Fan charts, survival curves, target odds and a sensitivity ranking that tells you which lever is worth pulling first.
03 — What you get
Six answers a spreadsheet cannot give you.
All of it free, all of it exportable. We gate saving, never the answer.
Confidence bands
P10 through P90 for revenue, customers and cash, every month. The width of the band is the honest part.
Survival odds
What share of runs make it to month 24, when the failures die, and how much of that hangs on a round closing.
Target probabilities
Not "you will hit €100K in M18" — you hit it in 28% of runs. Set your own targets and watch the odds move.
Sensitivity ranking
Which input actually moves the outcome. Usually churn, and usually by more than everything else combined.
Scenario comparison
PLG against sales-led against raising. Same starting cash, side by side, risk plotted against reward.
The full audit trail
Every formula, every input, every percentile as CSV. An investor can check the number themselves.
04 — Who it is for
For anyone who has to defend a number.
Founders raising
You need a model that survives a partner meeting. Ranges and stated assumptions read as rigor; a single hockey stick reads as hope.
Product managers
You are building a business case for one bet. This gives you the downside case before someone else finds it for you.
Product leaders planning
Annual planning across a portfolio. You want to know which assumption the whole plan is quietly resting on.
Anyone with 18 months of runway
You want to know how long you actually have, in the version where the round does not land.
The model lives in your browser. Close the tab and it is gone.
That is the only thing an email changes — somewhere to keep it, and a link you can send. Running it, reading it and exporting it never needs one.
We do not share your email. No drip campaign — one message with your link.
No email needed
- Build the model
- Run 10,000 simulations
- Every chart and probability
- Export the full audit trail
With an account
- Saved models and version history
- A read-only link to share
- Scenario comparisons kept
- Push assumptions into Shorter Loop
04 — After the forecast
A forecast is a pile of assumptions. Shorter Loop tracks them.
The simulator tells you which assumption your plan depends on. The hard part is what happens over the next six months — whether anyone checks it. That is the product this tool comes from.
Assumed
Every input starts as a claim
Churn of 2%, NRR of 110%, a round closing in month six. Real numbers in the model, evidence for none of them.
Evidenced
A real month settles it
Push them across and each becomes a tracked item. When actuals arrive, the status flips and the forecast updates with it.
Reference
The decision keeps its receipt
Six months on, the plan still says what it assumed, what proved out, and who decided. That is the whole point of the loop.
Questions
The ones people actually ask.
Is it really free, including the export?
Yes, including the export. An email only buys you saving and sharing. We would rather you used it and told someone.
What is Monte Carlo simulation, in one sentence?
Instead of computing your model once with your best guesses, we compute it 10,000 times with different values drawn from your ranges, then count how the outcomes fell.
How accurate is the forecast it produces?
As accurate as your ranges. Garbage in, garbage out — but a wide range in produces a visibly wide answer out, which is more honest than a precise wrong number.
Where does my data go when I use this?
Nowhere, unless you save. The model runs in your browser and stays there. Saved models sit in the EU, in Frankfurt.
Can I use it for a non-SaaS business?
Yes — marketplace, e-commerce, transactional, advertising, hardware and usage-based all have their own canvas, with their own benchmarks.
Do I need Shorter Loop to use the simulator?
No. It is a standalone tool. It happens to hand off cleanly if you already use us, or want to.
Stop planning against one number.
Five minutes of setup, three seconds of simulation, and a forecast you can actually defend.