Project a balance with monthly additions, compounding frequency and deposit timing, including zero or negative rates.
Enter values, then calculate.
How the calculation works
Choose nominal annual rate r, compounds per year n and a term containing whole months M. We use an equivalent monthly rate q = (1 + r/n)^(n/12) − 1. Balance = P(1+q)^M + C((1+q)^M−1)/q for end-month deposits; beginning-month deposits multiply the contribution part by (1+q). At zero rate, balance is P + C×M.
Example and verification
1,000 initially plus 100 monthly for one year at 0% gives 2,200, with 1,200 added and zero interest. With no additions, 1,000 at 10% compounded annually for two years gives 1,210.
Software checks cover the example, invalid input, zero or boundary cases, and reset in Chromium. No physical measurements or all-browser certification are claimed.
Scope and limitations
This is a fixed-rate mathematical scenario, not investment advice or a promised return. Fees, tax, inflation, changing rates and withdrawal rules are excluded. The equivalent-month convention may differ from a provider’s actual credit dates; daily means 365 compounds per year. Currency selection changes the label, not the value.
Common questions
Can the growth be negative?
Yes. A negative fixed rate reduces the projected balance. A hypothetical rate is not a forecast of market performance.
Technical references
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Maintained by GadgetsFocus. Updated 2 October 2026 with AI-assisted writing and translation review; no human native-speaker or clinical review is claimed.