Weekly Compound Interest Calculator
Interest added every week — 52 times a year. Adjust the inputs to see the year-by-year effect.
Year-by-Year Breakdown
| Year | Starting Balance | Contributions | Interest Earned | Ending Balance |
|---|---|---|---|---|
| 1 | $10,000 | $6,000 | $1,058 | $17,058 |
| 2 | $17,058 | $6,000 | $1,645 | $24,703 |
| 3 | $24,703 | $6,000 | $2,281 | $32,984 |
| 4 | $32,984 | $6,000 | $2,971 | $41,955 |
| 5 | $41,955 | $6,000 | $3,717 | $51,672 |
| 6 | $51,672 | $6,000 | $4,526 | $62,197 |
| 7 | $62,197 | $6,000 | $5,402 | $73,599 |
| 8 | $73,599 | $6,000 | $6,351 | $85,950 |
| 9 | $85,950 | $6,000 | $7,378 | $99,328 |
| 10 | $99,328 | $6,000 | $8,492 | $113,820 |
| 11 | $113,820 | $6,000 | $9,698 | $129,517 |
| 12 | $129,517 | $6,000 | $11,004 | $146,521 |
| 13 | $146,521 | $6,000 | $12,419 | $164,940 |
| 14 | $164,940 | $6,000 | $13,952 | $184,892 |
| 15 | $184,892 | $6,000 | $15,612 | $206,505 |
| 16 | $206,505 | $6,000 | $17,411 | $229,916 |
| 17 | $229,916 | $6,000 | $19,359 | $255,275 |
| 18 | $255,275 | $6,000 | $21,470 | $282,745 |
| 19 | $282,745 | $6,000 | $23,756 | $312,500 |
| 20 | $312,500 | $6,000 | $26,232 | $344,732 |
| 21 | $344,732 | $6,000 | $28,914 | $379,647 |
| 22 | $379,647 | $6,000 | $31,820 | $417,467 |
| 23 | $417,467 | $6,000 | $34,967 | $458,434 |
| 24 | $458,434 | $6,000 | $38,377 | $502,811 |
| 25 | $502,811 | $6,000 | $42,070 | $550,880 |
| 26 | $550,880 | $6,000 | $46,070 | $602,951 |
| 27 | $602,951 | $6,000 | $50,403 | $659,354 |
| 28 | $659,354 | $6,000 | $55,097 | $720,451 |
| 29 | $720,451 | $6,000 | $60,182 | $786,633 |
| 30 | $786,633 | $6,000 | $65,690 | $858,323 |
| Total | — | $190,000 | $668,323 | $858,323 |
How much does weekly compounding really change?
Weekly sits between monthly and daily and is very close to both. If you are choosing between accounts, the quoted APY already folds the compounding frequency in — compare APY, not frequency.
The table below holds everything constant — $10,000 at 5% for 10 years, no contributions — and varies only the compounding cadence.
| Frequency | Times / year | Final balance | vs annual |
|---|---|---|---|
| Daily | 365 | $16,486.65 | +$197.70 |
| Weekly (this page) | 52 | $16,483.25 | +$194.31 |
| Monthly | 12 | $16,470.09 | +$181.15 |
| Quarterly | 4 | $16,436.19 | +$147.25 |
| Annual | 1 | $16,288.95 | — |
The spread across every cadence is $197.70 — under 1.2% of the balance. Raising the rate by a quarter of a point, or adding a small monthly contribution, moves the result far more than any change of frequency. Try it in the calculator above.
Where you meet weekly compounding
Weekly compounding is uncommon in retail banking. You will mostly meet it in short-term lending, some peer-to-peer platforms, and in modelling exercises where a weekly cadence matches a weekly pay cycle.
Other compounding frequencies
Related Calculators
Frequently Asked Questions
- Interest is calculated and added to your balance every week — 52 times a year. From the next period onward you earn interest on that interest too. Weekly compounding is uncommon in retail banking. You will mostly meet it in short-term lending, some peer-to-peer platforms, and in modelling exercises where a weekly cadence matches a weekly pay cycle.