Debtor Days Calculator
How long customers take to pay.
Enter your values
Enter the accounts receivable in $.
Enter the revenue in period in $.
Enter the days in period you are working with.
Enter the payment terms in days.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Debtor days (DSO)
- 18.4 days
- Against terms
- Within terms
- Daily sales
- $4,666.67
- Cash freed if on terms
- $0.00
Quick answer
Debtor days show the average time between invoicing and getting paid.
DSO = receivables ÷ revenue × days
At a glance
| What it does | How long customers take to pay. |
|---|---|
| Category | Business |
| Inputs needed | Accounts receivable, Revenue in period, Days in period, Payment terms |
| Main output | Debtor days (DSO) |
| Formula | DSO = receivables ÷ revenue × days |
| Cost | Free — no sign-up, no download |
How to use the Debtor Days Calculator
- 1Enter the receivables balance.
- 2Enter revenue over the same period.
- 3Enter your standard payment terms.
Inputs explained
- Accounts receivable($)
- Enter the accounts receivable in $.
- Revenue in period($)
- Enter the revenue in period in $.
- Days in period
- Enter the days in period you are working with.
- Payment terms(days)
- Enter the payment terms in days.
Worked example
Using the values the calculator loads with:
Inputs
- Accounts receivable86000 $
- Revenue in period420000 $
- Days in period90
- Payment terms30 days
Results
- Debtor days (DSO)18.4 days
- Against termsWithin terms
- Daily sales$4,666.67
- Cash freed if on terms$0.00
Frequently asked questions
How do I reduce DSO?
Invoice immediately, chase at day 7 and offer card payment.
Is 45 days bad?
It is common in B2B but ties up a month and a half of sales.
What do I need to enter into the Debtor Days Calculator?
Just 4 values: accounts receivable, revenue in period, days in period, payment terms. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Debtor Days Calculator work out the answer?
Debtor days show the average time between invoicing and getting paid. It applies the formula DSO = receivables ÷ revenue × days and shows the working so you can check each step by hand.
Is the Debtor Days Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.