Invoice Due Date Calculator

Calculate invoice due dates and early payment discount deadlines.

About Invoice Due Date Calculator

Taking a two per cent discount twenty days early annualises to roughly 37 per cent, which almost always exceeds the cost of capital. That is why early payment discounts are usually worth taking. For the supplier the same arithmetic runs in reverse: offering 2/10 net 30 is expensive financing compared with most borrowing.

Formula

Invoice Due Date

Annualised discount = discount ÷ (100 − discount) × 365 ÷ days saved

2/10 net 30: Two per cent discount if paid within ten days, otherwise due in thirty
annualised rate: The effective return on paying early rather than holding the cash

Worked example

With the default values below, Invoice Due Date Calculator returns Days Until Due of 24. Change any input above and every figure here is recalculated in your browser.

Inputs used

Invoice amountminimum 0: 12,000
Payment termminimum 0 days: 30 days
Early payment discountaccepts 0–20 %: 2 %
Discount windowminimum 0 days: 10 days
Days since the invoice dateminimum 0 days: 6 days

Results

Days Until Due: 24 days
Early Payment Discount: $240.00
Amount if Paid Within the Window: $11,760.00
Annualised Value of Taking the Discount: 37.24%
Status: Within the early payment discount window

Step by step

1Values used
2Invoice Due Date
3Days Until Due= 24 days
4Early Payment Discount= 240.00
5Amount if Paid Within the Window= 11,760.00
6Annualised Value of Taking the Discount= 37.24
7Status= Within the early payment discount window

Assumptions and limits

The result is derived only from the 5 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.
This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

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

Frequently Asked Questions

How is Invoice Due Date calculated?

Annualised discount = discount ÷ (100 − discount) × 365 ÷ days saved Taking a two per cent discount twenty days early annualises to roughly 37 per cent, which almost always exceeds the cost of capital. That is why early payment discounts are usually worth taking.

Why does Invoice Due Date matter?

For the supplier the same arithmetic runs in reverse: offering 2/10 net 30 is expensive financing compared with most borrowing.

What values do I need to enter?

This calculator takes 5 inputs: Invoice amount, Payment term, Early payment discount, Discount window, Days since the invoice date. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.