Enter the total annual percentage (e.g., Base Rate + Statutory Margin)
Days Overdue:0 days
Daily Interest Amount:0.00
Total Statutory Interest:0.00
Total Amount Payable:0.00
Understanding Statutory Interest on Debts
Statutory interest refers to the legal right to charge interest on overdue payments. Whether you are a business chasing a commercial debt or enforcing a court judgment, applying the correct statutory rate is crucial for recovering the full value of the money owed to you.
Statutory interest is typically applicable in two main scenarios:
Commercial Debts: Late payment legislation often allows businesses to charge interest on overdue invoices from other businesses. In many jurisdictions, this is a fixed percentage above the central bank base rate.
Court Judgments: Once a court judgment is issued, interest usually accrues on the judgment debt at a statutory rate until payment is made in full.
How to Use This Calculator
This tool calculates simple interest based on the standard legal formula. To get an accurate figure:
Principal Debt Amount: Enter the original amount of the invoice or debt, excluding any previous interest or unrelated costs.
Statutory Rate: Input the annual interest rate. For example, in the UK, statutory interest on commercial debts is the Bank of England Base Rate plus 8%. In the US, post-judgment interest rates are set by federal or state statutes.
Dates: Enter the date the payment was originally due and the date you are calculating for (usually today or the date payment was finally received).
Compensation and Collection Costs
In addition to statutory interest, legislation in many regions (such as the Late Payment of Commercial Debts Act) allows creditors to claim a fixed sum of compensation for debt recovery costs. This calculator focuses solely on the interest component of your claim.
Why Accurate Calculation Matters
Calculating statutory interest correctly is vital for legal compliance. Overstating your claim can lead to legal challenges or the dismissal of your demand, while understating it results in financial loss. This calculator provides a precise breakdown of the daily accrual and total accumulated interest based on the inputs provided.
function calculateStatutoryInterest() {
// 1. Get DOM elements
var debtInput = document.getElementById("debtAmount");
var rateInput = document.getElementById("statutoryRate");
var dateDueInput = document.getElementById("dueDate");
var dateCalcInput = document.getElementById("calcDate");
var resultsDiv = document.getElementById("results");
// 2. Parse values
var principal = parseFloat(debtInput.value);
var rate = parseFloat(rateInput.value);
var date1 = new Date(dateDueInput.value);
var date2 = new Date(dateCalcInput.value);
// 3. Validation
if (isNaN(principal) || principal date2) {
alert("The calculation date cannot be before the due date.");
return;
}
// 4. Calculate Time Difference (Days)
// One day in milliseconds = 24 * 60 * 60 * 1000
var diffTime = Math.abs(date2 – date1);
var diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24));
// 5. Calculate Interest
// Formula: (Principal * Rate * Days) / 365 / 100
// We divide by 100 because rate is entered as percentage (e.g. 8)
var annualInterest = principal * (rate / 100);
var dailyInterest = annualInterest / 365;
var totalInterest = dailyInterest * diffDays;
var totalPayable = principal + totalInterest;
// 6. Display Results
document.getElementById("resDays").innerHTML = diffDays + " days";
document.getElementById("resDaily").innerHTML = dailyInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resInterest").innerHTML = totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotal").innerHTML = totalPayable.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
// Show results area
resultsDiv.style.display = "block";
}
// Set default dates for user convenience (Today)
var today = new Date();
document.getElementById('calcDate').valueAsDate = today;