My Premium Bonds Performance
Track your actual winnings and see how you're performing against the statistical odds
Your Monthly Data
Understanding Your Results
- Expected returns use Monte Carlo simulation. We run 10,000 simulations to calculate realistic expected winnings with actual prize amounts (£25, £50, £100, etc.).
- Longer tracking periods give better insights. Variance can be significant over short timeframes. Switch between 6 and 12 months to see trends.
- Your data is preserved when toggling. Switching between 6 and 12 months only changes what's displayed - all 12 months of data remain saved.
- Prize rates vary by month. The calculator automatically adjusts expected returns based on the NS&I rates that were in effect each month.
- Auto-populate uses median expected winnings. Your actual winnings will differ - click "Edit All" to update with your real winnings for accurate tracking.
- Your data is private. All calculations happen in your browser and nothing is sent to any server.