Savings goal calculator
Your savings plan
Inputs changed. Calculate again to update this plan.
- Final balance
- Already saved
- New contributions
- Total of your money
- Estimated interest
- Above your goal
Plan inputs
Full monthly schedule
| Month | Date | Contribution | Interest | Balance |
|---|
Constant APY; interest before each monthly deposit. No tax, fees or changes in yield. Interest is not rounded each month; displayed amounts are rounded to cents.
How this plan is calculated
Monthly amount finds the smallest fixed contribution, in whole cents, that reaches your goal by the last complete monthly deposit date. Time to goal finds the first monthly date that reaches your goal with the contribution you enter.
The plan starts today in your local calendar. Each deposit date keeps today's day of the month, or uses the last day when that month is shorter. A plan starting on January 31 therefore uses February 28 (29 in a leap year), then March 31. Deposits happen after interest is added.
Only complete months count. Days between the last monthly date and your target date receive no extra interest or deposit. The result shows the date calculated through and any days left out.
APY, rounding and limits
Annual percentage yield (APY) includes compounding. We use the equivalent monthly multiplier q = (1 + APY / 100)^(1/12). Each monthly balance is previous balance × q + contribution. Twelve model months give one full year of the chosen yield.
Interest stays unrounded during the calculation. For a required contribution, we check that the chosen number of cents reaches the goal and one cent less does not. The same deposit is used every month, so the final balance may be slightly above your goal.
Use one currency throughout; changing it does not convert any amount. Money inputs support up to 1,000,000,000 units with two decimal places. APY supports 0–100% with up to six decimal places. The model covers up to 1,188 months (99 years). A goal beyond that limit is not necessarily impossible.
Sources
- CFPB: annual percentage yield calculation explains how APY reflects compounding. The disclosure rules use day counts; our equal-month model is a planning assumption.
- Carnegie Mellon: equivalent interest periods, section 7.3 explains the relationship between periodic and effective annual rates.
The calculator, calendar rules and explanation are our own.
This is a constant-yield scenario, not a bank account forecast or personal financial advice. It excludes tax, fees, inflation and changing rates. For the broader question of how a balance grows, try Compound Interest Tool.