Measure a move in relative terms — how your balance changed over a week, or how far an instrument moved from where you entered.
An account going from 8,000 to 9,200 changed by (9,200 − 8,000) ÷ 8,000 × 100 = +15%.
All nine calculators are also in the Growstones app for iPhone and Android — alongside position sizing, a growth simulator and a weekly journal. Your data stays in your iCloud.