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Savings growth calculator

Build a transparent regular-saving scenario. Choose contribution timing, term, tax model and inflation. The schedule shows monthly progress; the goal date is the first month-end when the after-tax nominal balance reaches your target, not a guaranteed date.

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Data: 2026

Calculator

Enter data

Initial and monthly contributions, nominal rate, term, tax, inflation and goal. Fields marked with an asterisk are required.

How to use the calculator

  1. Set amounts and horizon. The nominal annual rate is divided by 12; it is not an effective annual rate.
  2. Choose tax and inflation assumptions. Inspect the schedule; a negative rate lets you test a decline.

Calculation details

Formula and calculation method

Each month adds the contribution and interest at annual rate / 12. Real value = net result / (1 + inflation)^(months/12). Tax applies only to positive gains under the selected model.

Worked example

PLN 1,000 initially plus PLN 100 each month for 12 months at 0% gives PLN 2,200. A PLN 2,000 goal is first reached at the end of month 10.

Limitations

  • Tax options compare models, not product eligibility or a PIT return. Fees, irregular contributions, variable rates and loss relief are excluded. No-tax mode does not establish an exemption.
  • Real value discounts the final balance to start-date prices; it is not a real return on differently dated contributions. The goal is checked only at month end.

Sources

Engine version: 2.0 (2026-09-22) · Last reviewed: 22 September 2026

Frequently asked questions

Does contributing at month start matter?

Yes: that contribution earns the month’s return. With a positive rate the final balance is higher; with a negative rate it can be lower.

What does “not within selected period” mean?

The goal was not reached at any checked month end. The calculator does not assume it will be reached later or extend the horizon automatically.

Read the supporting guide

Deposits, bonds, savings and ROI — what should be compared?

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