Interest On Delayed Payment Calculator

Work out interest on delayed payment instantly with clear inputs, formula shown and shareable results.

About Interest On Delayed Payment Calculator

Late payment statutes typically entitle a supplier to interest at a reference or central bank rate plus a fixed statutory margin, running from the day after the contractual due date. The entitlement usually applies automatically, without any need for a clause in the contract.

Formulas

Applicable rate

Rate = Statutory reference rate + Statutory margin

Interest

Interest = Invoice amount x Rate x Days late / 365

Worked example

With the default values below, Interest On Delayed Payment Calculator returns Statutory interest due of $21,610.96. Change any input above and every figure here is recalculated in your browser.

Inputs used

Invoice amount outstanding: 850,000
Statutory reference or base rate: 6.5
Statutory margin above the reference rate: 8
Days past the due date: 64

Results

Statutory interest due: $21,610.96
Applicable annual rate: 14.50%
Total payable including interest: $871,610.96
Interest accruing per day: $337.67

Step by step

1Values used
2Applicable rate
3Interest
4Statutory interest due= 21,610.96
5Applicable annual rate= 14.50
6Total payable including interest= 871,610.96
7Interest accruing per day= 337.67

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Indicative estimate only. Fees, entitlements, limits and formulas vary by jurisdiction, statute, policy wording and the facts of the case. This is not legal, tax, insurance or financial advice — confirm with a qualified professional or the relevant authority.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Indicative estimate only. Fees, entitlements, limits and formulas vary by jurisdiction, statute, policy wording and the facts of the case. This is not legal, tax, insurance or financial advice — confirm with a qualified professional or the relevant authority.

Frequently Asked Questions

Do I have to claim the interest to be entitled to it?

The entitlement usually arises automatically, but in practice it has to be invoiced and pursued. Many suppliers waive it to preserve the relationship.

Can a contract exclude statutory late payment interest?

Only within limits. Many regimes void terms that exclude or substantially reduce the statutory remedy.