Default Interest Calculator

Calculate overdue charges with caps, taxes, and recoveries. Review interest growth clearly across every overdue day with charts.

Enter Default Interest Inputs

Example Data Table

Input Sample Value Explanation
Overdue Principal 10,000.00 Amount unpaid after due date.
Annual Default Rate 12% Default rate applied to overdue balance.
Days Overdue 45 Total calendar days in default.
Grace Days 5 Days excluded before charging default interest.
Fixed Penalty Fee 50.00 One-time late charge.
Penalty Fee on Principal 1.5% Additional percentage-based penalty.
Tax on Charges 5% Tax applied to interest and penalties.
Partial Recovery 2,000.00 on day 20 Payment reduces outstanding balance later.

Formula Used

Daily Default Rate = Annual Default Rate ÷ Day Count Basis

Chargeable Days = Max(0, Days Overdue − Grace Days)

Daily Interest = Outstanding Balance × Daily Default Rate

Simple Gross Interest = Sum of each day’s interest + Prior Accrued Interest

Penalty Amount = Fixed Penalty Fee + (Overdue Principal × Penalty %)

Tax Amount = (Gross Interest + Penalty Amount) × Tax Rate

Uncapped Charges = Gross Interest + Penalty Amount + Tax Amount

Final Charges = Minimum(Uncapped Charges, Charge Cap)

Total Amount Due = Overdue Principal + Final Charges

If partial recovery is entered, the calculator reduces the balance on the chosen day, then continues the accrual on the lower amount.

How to Use This Calculator

  1. Enter the overdue principal and annual default interest rate.
  2. Provide total overdue days and any grace days allowed.
  3. Select the day count basis and accrual method.
  4. Add fixed penalties, percentage penalties, and tax rate if needed.
  5. Enter prior accrued interest for rolled-forward defaults.
  6. Add any partial recovery amount and the day it was received.
  7. Choose a cap type if your agreement limits recoverable charges.
  8. Press calculate to show totals, chart, and exportable daily schedule.

Frequently Asked Questions

1. What is default interest?

Default interest is an extra rate charged when a borrower misses a payment or breaches a loan term. It usually applies only after the due date or grace period ends.

2. How is default interest different from normal interest?

Normal interest applies during regular loan performance. Default interest is a higher rate triggered by late payment or default, and it may be combined with penalties and taxes.

3. Why does day count basis matter?

A 360-day basis produces slightly higher daily charges than a 365-day basis. Agreements often specify the basis, so matching it improves accuracy and compliance.

4. When should I use compounding?

Use compounding only if the contract permits capitalizing overdue interest. Many agreements use simple accrual, while some institutional facilities allow daily or monthly compounding.

5. Can I include a partial recovery payment?

Yes. Enter the recovered amount and the day it was received. The calculator reduces the outstanding balance from that point onward, which lowers later interest charges.

6. What does the charge cap do?

The cap limits recoverable charges either by a fixed amount or by a percentage of principal. This helps model contractual ceilings or policy restrictions on late charges.

7. Are taxes included in the result?

Yes, when you enter a tax or VAT rate. The calculator applies tax to interest and penalties, then adds it to the final charges before calculating the full amount due.

8. Is this calculator suitable for legal enforcement?

It is useful for estimation, internal review, and negotiation support. For formal notices, litigation, or regulated lending disputes, verify the exact contract wording and local rules.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.