Understand the assumptions.
Savegrove offers 30 educational savings models, not individualized financial advice, bank offers or forecasts. The example amounts and rates are editable inputs. All calculator results are scenarios, before costs not explicitly modeled.
APY and nominal interest
APY includes compounding over a year. Where monthly deposits are modeled, Savegrove converts the entered APY to an equivalent monthly rate using (1 + APY)^(1/12) − 1. The nominal-rate conversion tools instead use an explicit compounding frequency. The simple-interest tool does not compound interest. These simplified models do not reproduce all disclosure rules, tiers or day-count conventions used by an institution.
Contributions and timing
Most monthly models assume end-of-month deposits. The compound-savings and monthly-goal tools allow beginning-of-month deposits instead. Contributions are equal unless the growing-contributions tool explicitly applies an annual increase. Time-to-goal counts monthly periods, up to 100 years. No actual calendar dates, market returns, tax rules or holidays are inferred.
Inflation, fees and taxes
Inflation tools use the constant percentage you enter. Purchasing power and real return are distinct from nominal balance. The one-year tax tool applies a flat user-entered rate to interest, ignoring allowances, brackets and timing. The fee model deducts monthly fees after interest without creating negative account balances. Withdrawal runway includes the last partial withdrawal. Actual terms may differ.
Budgeting and cash buffers
Emergency-fund month counts are your chosen assumptions, not a recommendation to hold any particular amount. The 50 / 30 / 20 tool is only an illustrative split. Avoided spending becomes savings only if it is actually kept rather than redirected to other spending.
Rounding and currency
Calculations use JavaScript floating-point arithmetic without rounding each monthly step. Results are rounded for display. You may need to round actual contributions upward to cover a goal. Choose a display currency; no exchange-rate conversion is performed. Large or invalid projections are rejected.
Educational references
- Investor.gov: Compound Interest Calculator — contributions, periods and compounding as separate assumptions.
- CFPB: Annual Percentage Yield Calculation — the distinction between annualized yield, principal and interest.
- CFPB: Building an Emergency Fund — planning a dedicated buffer for unexpected costs.
These references inform terminology and educational context. Savegrove is independently built and is not endorsed by those organizations. Its calculations are implemented in the included source and tests.
Open source
Created with AI assistance for this project. Source code and tests are available under the MIT License. See the source guide. No financial account access, external calculation API or third-party finance library is used.