Understand your uncertainty
before it becomes a problem.
Pick a distribution, visualize outcomes, and explore Pr(x < X) interactively. No code required — just write simple expressions and see what your data is trying to tell you.
How it works
Three steps from guess to insight
No stats degree required. If you can write a spreadsheet formula, you can use Probability Playground.
Pick a distribution
Choose from Normal, Uniform, Poisson, Gamma, and more. Set your parameters — mean, standard deviation, bounds, whatever describes your situation.
Set parameters
Define your variables using simple expressions. Combine distributions, add constraints, or chain calculations together.
Read the histogram
See the full range of outcomes as a histogram. Drag the probability line to explore Pr(x < X) for any threshold — no math degree required.
Features
Built for real business decisions
Whether you're estimating budgets, forecasting demand, or sizing inventory, Probability Playground helps you see the full picture.
Visual histogram
See the full distribution of outcomes at a glance. Identify where results cluster and where the tails are — not just a single point estimate.
Draggable Pr(x < X) line
Drag a threshold line across the histogram to see the exact probability of any outcome. No manual calculations needed.
Mini-language editor
Write simple expressions like revenue ~ norm(500, 50) or profit = revenue - cost. Combinations are just arithmetic.
Save & share
Create a free account to save your models and share them with colleagues. Revisit any model to update parameters and re-run.
10+ distribution types
Normal, Uniform, Poisson, Binomial, Gamma, Beta, Exponential, and more — each with a plain-English description of when to use it.
Instant results
Run thousands of simulations in milliseconds. Adjust parameters and see results update in real time.
Use cases
Know your odds before you commit
Use Probability Playground wherever you're making decisions under uncertainty.
Budget forecasting
Model revenue as a range instead of a single number. See how uncertainty in sales affects your bottom line — and what it means for cash flow.
Inventory planning
Set demand as a distribution instead of a guess. See how much safety stock you need to hit your service level targets.
Project estimation
Model task durations with ranges instead of best-case numbers. See the probability of hitting your deadline before you promise it.
Marketing ROI
Model conversion rates, traffic, and average order value as distributions. See the range of possible outcomes for your campaign.
Risk analysis
Combine multiple uncertain inputs to see the full range of outcomes — and the probability of hitting any threshold you care about.
Capacity planning
Model arrival rates and service times as distributions. See how utilization and wait times vary under different demand scenarios.
Ready to see your uncertainty clearly?
Start exploring distributions in seconds — no account required, free forever.
Try Probability Playground