Free tools

Trading calculators for clearer decisions

Check statistical significance, trading expectancy, and risk-based position size without signing in. These are reference tools, not trading advice.

01 · Multiple-testing significance calculator

See how searching raises the bar

For anyone comparing several versions of one trading idea, this shows why the best-looking result needs stronger evidence as the search grows.

Corrected significance bar

t ≥ 3.02

Testing 20 variations means a single result needs to be about as unlikely as a 1-in-400 event before it's worth trusting — not 1-in-20.

Per-test alpha: 0.002500 · Family-wide alpha: 0.05

This is a simplified illustration of the same principle Mithos applies automatically to every strategy you build — the real calculation also accounts for your recent activity across all your strategies, not just this one idea.

02 · Trading expectancy calculator

Look beyond win rate

For traders checking whether their average winner, average loser, and win rate combine into a positive result before costs.

%
R
R

Expectancy per trade

0.005R

A positive number means this combination of win rate and win/loss size would be profitable on average, before costs. A negative number means it wouldn't be — regardless of how often it wins.

Costs are not included in this simplified tool. The real Mithos rigor harness applies a separate cost floor check.

03 · Position size calculator

Size a trade from the risk first

For traders who know their account size, chosen risk percentage, and stop distance, and want a consistent stake or position value.

£
%
pts
Risk amount
£100.00
Stake per point
£4.00/pt

Risk amount ÷ stop distance gives the maximum stake per point.