High-Yield Savings Calculator
Model an opening savings balance with recurring deposits or withdrawals under an entered APY. Select beginning- or end-of-month timing, and the calculator will reject a withdrawal schedule that exhausts the account during the projection.
How to use this calculator
Enter initial balance, signed monthly cash flow, cash-flow timing, entered APY, and projection time.
Review variable-rate terms, compounding frequency, account fees, balance tiers, withdrawal limits, tax, and deposit-insurance coverage.
Read projected balance, initial balance plus net cash flow, recurring net cash flow, and projected growth.
Formula
Monthly rate i = (1 + APY)^(1/12) − 1. End timing uses balance × (1+i) + cash flow; beginning timing uses (balance + cash flow) × (1+i), with withdrawals entered as negative.
Worked example
A $5,000 opening balance at 4.00% APY with $100 deposited at each month end models 12 deposits plus APY-based monthly growth over one year.
Assumptions and limits
- The APY and signed cash flow remain constant; negative cash flow cannot take the balance below zero, and actual bank rates, tiers, fees, and taxes may differ.
- High-Yield Savings Calculator treats the entered values as estimates and does not infer missing project, account, or personal details.
- Calculations retain working precision except where the cited method requires an intermediate rounding step; displayed values are then formatted separately. Source rules and dated rates must be rechecked when they change.
Sources
- Federal Deposit Insurance Corporation: Deposit Insurance at a GlanceDeposit-account ownership and insurance-limit context. Reviewed 2026-08-14.
- U.S. Securities and Exchange Commission: Compound Interest CalculatorCompound-growth inputs and future-value concepts. Reviewed 2026-08-14.
- Consumer Financial Protection Bureau: Annual percentage yield — Regulation DD § 1030.2(c)Official formula or method source used by this calculator. Reviewed 2026-08-14.
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Verification
How this calculator is checked
Trust comes from reproducible evidence, not model confidence. You can inspect the formula, assumptions, worked example, and cited sources on this page.
- Versioned calculationFormula logic is kept separate from the interface and covered by automated registry and behavior checks.
- Cited evidenceSources linked for independent checking: 3.
- Transparent AI useAI may assist drafting or adversarial review. Agreement between models is not proof, and no human expert review is claimed unless a named reviewer is shown.
Frequently asked questions
How does the High-Yield Savings Calculator work?
Monthly rate i = (1 + APY)^(1/12) − 1. End timing uses balance × (1+i) + cash flow; beginning timing uses (balance + cash flow) × (1+i), with withdrawals entered as negative.
What information should I enter in the High-Yield Savings Calculator?
Enter initial balance, signed monthly cash flow, cash-flow timing, entered APY, and projection time, then verify variable-rate terms, compounding frequency, account fees, balance tiers, withdrawal limits, tax, and deposit-insurance coverage.
What should I verify before using this High-Yield Savings Calculator result?
The APY and signed cash flow remain constant; negative cash flow cannot take the balance below zero, and actual bank rates, tiers, fees, and taxes may differ.
Last updated 2026-08-25 · apy-signed-cashflow-v2 · content-2026-08-14 · Published by YunFanLabs