Calculator
Polish statutory interest calculator
This statutory interest compensates for use of capital under Article 359 of the Polish Civil Code. It is not late-payment interest. The calculator splits the date range at each rate change and shows the day count for each period.
Calculator
Enter data
Automatic rates: 1 January 2025–22 September 2026; commercial rates only from 1 January 2026. Fields marked with an asterisk are required.
How to use the calculator
- Enter first and last accrual day; both are included.
- Automatic mode splits periods on rate changes. Manual mode assumes one constant rate; calculate separate intervals if it changes. Do not confuse maximum and statutory rates.
Calculation details
Formula and calculation method
Sum of principal × annual percentage rate × days / 36500; actual days with a fixed 365 denominator. Period amounts are not rounded before summing. Civil result to cents; tax result to whole PLN after testing the unrounded total against PLN 8.70.
Worked example
PLN 10,000 capital from 5 to 14 March 2026 inclusive: ten days at 7.25%, giving PLN 19.86 statutory capital interest.
Limitations
- Automatic rates: 1 January 2025–22 September 2026; commercial rates only from 1 January 2026.
- One unchanged debt, without partial payments, compounding, collection charges, accrual suspensions or limitation-period assessment. Selecting a mode does not establish legal entitlement.
Sources
Engine version: 1.0 · Last reviewed: 22 September 2026
Frequently asked questions
What does this tool cover?
This statutory interest compensates for use of capital under Article 359 of the Polish Civil Code. It is not late-payment interest. The calculator splits the date range at each rate change and shows the day count for each period.
Which assumptions should I verify?
Automatic rates: 1 January 2025–22 September 2026; commercial rates only from 1 January 2026. One unchanged debt, without partial payments, compounding, collection charges, accrual suspensions or limitation-period assessment. Selecting a mode does not establish legal entitlement.
Are entered values stored?
Calculations run locally in your browser. Entered identifiers, amounts and results are not stored or sent to analytics.