BrightComb Compound Simulator
The Power of Compound Interest
See what time, rate and discipline do to money. Free for the basics, Pro for the full picture.
Data updated: 2026-09-29
How access works
- Enter your email, we send you a link. No password to remember.
- Click the link in the mail. You are signed in with a free account.
- Want Pro? Pay once (12 months). Pro is active right after payment.
- From then on just use Calculator, Compare or Bitcoin. Your browser stays signed in for 30 days; after signing out, request a new link and Pro is there again until it expires.
Base case
US$28,489
+184.9 % · You paid in US$10,000
Growth over time
Base caseBest case 🔒Worst case 🔒You paid in
Monte-Carlo simulation
The three lines above are fixed paths: one assumed return each. Monte-Carlo instead runs thousands of random paths from the asset's real year-by-year returns (without a selected asset: random returns around your rate). Read the result like this: in 9 of 10 runs you end above the pessimistic value, in half above the median, in 1 of 10 above the optimistic value. If the pessimistic value is below what you paid in, the plan carries real loss risk over this horizon.
Net of taxes, costs and inflation
Goal calculator
Required monthly contribution
US$224.30
15 years · 7.0 % p.a. · Initial investment US$10,000
Year-by-year breakdown
One payment, 12 months of access, nothing to cancel.
Best and worst case show what a few points of return do over decades. Monthly contributions and compounding frequency. Monte-Carlo: 2,000 simulated futures, with a probability of loss. Net of taxes, costs and inflation for your country.