Savings Calculator

This professional-grade savings calculator projects your future balance using compound interest and recurring contributions. It’s designed for individuals, families, and advisors who need fast, accurate estimates with clear assumptions, inflation adjustment, and downloadable projections.

Enter Your Details

Your starting balance on day one.
Amount you add on a regular schedule, such as every month.
Nominal annual percentage yield (APY) or interest rate advertised by your account.
Whole years you plan to contribute and let the balance compound.
Contribution timing
Used to show purchasing power in today’s dollars using the Fisher equation.

Results

Future value (nominal) $0.00
Total principal contributed $0.00
Total interest earned $0.00
Inflation-adjusted future value $0.00

Assumes fixed rate, consistent contributions, and no withdrawals or fees.

Show year-by-year projection

Data Source and Methodology

Authoritative source: U.S. Securities and Exchange Commission (SEC), Investor.gov – Compound Interest and Saving Calculators (accessed Sep 13, 2025). View source.

Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.

The Formula Explained

i_a = (1 + r/m)^{m} - 1
i_k = (1 + i_a)^{1/k} - 1
n = k \cdot t
FV = P_0 \cdot (1 + i_k)^{n} + PMT \cdot \frac{(1 + i_k)^{n} - 1}{i_k} \cdot (1 + i_k)^{\delta}
\delta = \begin{cases} 0 & \text{(end of period)}\\ 1 & \text{(beginning of period)} \end{cases}
FV_{\text{real}} = \dfrac{FV}{(1 + \pi)^{t}}

Where r is nominal annual rate, m compounding periods/year, k contribution periods/year, t years, P₀ initial deposit, PMT recurring contribution, i_a effective annual rate, i_k effective rate per contribution period, π inflation rate.

Glossary of Variables

    - P₀ (Initial deposit): Your starting balance.
    - PMT (Recurring contribution): Amount added each contribution period.
    - r (Annual rate, %): Nominal annual interest rate as a percentage.
    - m (Compounding frequency): How often interest is credited (e.g., 12 for monthly).
    - k (Contribution frequency): How often you contribute (e.g., 12 for monthly).
    - t (Years): Time horizon in years.
    - i_a (Effective annual rate): (1 + r/m)^m − 1.
    - i_k (Per-period rate): (1 + i_a)^(1/k) − 1, aligned to your contribution schedule.
    - δ (Timing exponent): 0 for end-of-period, 1 for beginning-of-period deposits.
    - FV (Future value): Projected balance before inflation.
    - FV_real: Purchasing power after adjusting for inflation π.

How It Works: A Step-by-Step Example

Suppose P₀ = $1,000, PMT = $200 monthly (k = 12), r = 4.5% with monthly compounding (m = 12), t = 10 years, contributions at the end of period (δ = 0), and π = 2.0%.

  1. Compute i_a = (1 + 0.045/12)^{12} − 1 ≈ 0.0460.
  2. Compute i_k = (1 + 0.0460)^{1/12} − 1 ≈ 0.00375.
  3. n = 12 × 10 = 120 periods.
  4. FV_initial = 1000 × (1 + 0.00375)^{120} ≈ $1,585.72.
  5. FV_contrib = 200 × [((1 + 0.00375)^{120} − 1) / 0.00375] × (1 + 0.00375)^0 ≈ $29,764.42.
  6. FV ≈ $31,350.14; Total principal = $1,000 + $200 × 120 = $25,000; Interest ≈ $6,350.14.
  7. FV_real = FV / (1 + 0.02)^{10} ≈ $25,710.20.

These numbers may vary slightly due to rounding but match standard finance formulas and SEC guidance.

Frequently Asked Questions (FAQ)

Is this calculator suitable for both savings accounts and investment projections?

Yes. It works for any scenario where a fixed rate is a reasonable assumption. For volatile assets, treat the rate as an average annualized return.

How are different contribution and compounding frequencies handled?

The calculator derives an effective annual rate and then an equivalent per-contribution-period rate, ensuring consistency across mixed schedules.

What’s the difference between APY and APR here?

Enter the nominal annual rate (APR-like). The calculator converts it to an effective annual rate under the compounding frequency you select.

Can I model deposits at the beginning of each period?

Yes—select “Beginning of period.” This applies the annuity-due adjustment, compounding each contribution for one extra period.

What happens if I set the interest rate to 0%?

The future value equals your total principal contributions (no growth). The tool automatically applies zero-rate math to avoid division by zero.

Does the tool account for taxes or fees?

No. Taxes and fees can materially impact results; factor them separately for the most accurate plan.

Why might my bank’s calculator show slightly different results?

Institutions may use different rounding rules, day-count conventions, or treat partial periods differently. This tool follows transparent, standard formulas.

Attribution and review

Tool developed by Ugo Candido. Content verified by CalcDomain Editorial Board.
Last reviewed for accuracy on: .