Example 1 — 30 days
- Amount: 5,000
- Rate: 10% annual
- 30 days, actual/365
Interest ≈ 41.10
Daily ≈ 1.37
Simple estimate: 5000 × 0.10 × (30/365).
Default interest
Estimate the cost of delay: overdue amount × annual rate × time late.
Educational estimate — not legal, tax, or accounting advice. Statutory, contractual, and local rules may differ. The result depends on the rate you enter. Not a loan instalment, APR, or amortization schedule.
Results
Enter data and click Calculate.
How results are calculated
Formula: interest ≈ amount × (rate%/100) × (days ÷ year base). Base = 365 (actual/365) or 360 (30/360). No compounding.
Dates: with both dates, days = calendar difference (or 30/360). The result depends on the rate you enter — we do not hardcode a statutory rate.
How to use
- Enter overdue amount, annual rate, and days (or dates in Advanced).
- Choose a day-count convention.
- Optionally compare scenario B (other days / rate).
- For payoff horizon → Debt repayment; for a loan payment → Loan instalment.
Examples
Example 2 — Dates
- Amount: 12,000
- 11.25% annual
- 2026-01-01 to 2026-03-15
Days from date range
Interest via actual/365
Instead of typing days by hand.
Example 3 — Scenario B
- 8,000 @ 10%, 60 days (30/360)
- B: 90 days @ 12%
Compare Δ interest
A vs B
Same amount, different time/rate.
FAQ
Is this legal advice or an official statutory rate?
No. This is a simplified educational estimate. Statutory, contractual, and local rules may differ — the result depends on the rate you enter.
How is interest calculated?
Interest ≈ amount × (rate%/100) × (days ÷ 365 or ÷ 360). No compounding.
How is this different from cost of loan or loan instalment?
Here: cost of paying late. Cost of loan / instalment are about offers and payments — not delay penalties.
How is this different from Debt repayment?
Debt repayment: “how long until zero?” at a fixed payment. Here: what the delay itself costs.
What does actual/365 vs 30/360 mean?
actual/365: calendar days ÷ 365. 30/360: month = 30 days, year = 360.
Where does currency come from?
From the page header.