# DSO Calculator – Days Sales Outstanding

URL: https://speedycalculator.com/calculators/finance/dso/
Last updated: 2026-10-25

> The DSO calculator works out days sales outstanding – the average number of days it takes a company to collect payment after a credit sale – from accounts receivable and credit sales.

## Inputs

- Beginning accounts receivable
- Ending accounts receivable
- Credit sales
- Days in the period
- Your payment terms (days)

## Results

- Days sales outstanding
- Days beyond terms
- Receivables turnover

## Formula

```
DSO = average accounts receivable ÷ credit sales × days in the period
Average AR = (beginning + ending AR) ÷ 2
```

## Explanation

Lower DSO means faster collection. Compare DSO with your payment terms: if you offer 30-day terms and DSO is 50, customers are paying late on average.

### How to use the DSO Calculator – Days Sales Outstanding

- **Beginning accounts receivable**
- **Ending accounts receivable**
- **Credit sales**
- **Days in the period**
- **Your payment terms**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter beginning and ending accounts receivable, credit sales for the period and the number of days.

### Tips

- Use consistent periods (a year or a quarter) for flow figures and period-end values for balances.
- Average opening and closing balances when a ratio mixes a flow with a stock.
- Benchmark against competitors in the same industry.
- Read the ratio together with others – profitability, liquidity and efficiency tell different stories.

### Common mistakes to avoid

- Using sales instead of cost of goods sold for inventory ratios.
- Mixing gross, operating and net profit.
- Ignoring one-off items that distort a single year.

### Inputs explained

FieldWhat to enterBeginning accounts receivableAmount in your currencyEnding accounts receivableAmount in your currencyCredit salesAmount in your currencyDays in the periodA numberYour payment termsIn days

### What each result means

- **Days sales outstanding** = ([Beginning accounts receivable] + [Ending accounts receivable])÷2÷[Credit sales]×[Days in the period]
- **Days beyond terms** = [Days sales outstanding] - [Your payment terms]
- **Receivables turnover** = [Credit sales]÷(([Beginning accounts receivable] + [Ending accounts receivable])÷2)

### Example values

How the main result changes when **Beginning accounts receivable** changes and everything else stays at the example values above:

Beginning accounts receivableDays sales outstanding (days)70,00035105,00040.3140,00045.6175,00050.9210,00056.3280,00066.9

## Worked example

Inputs — Beginning accounts receivable: $140,000; Ending accounts receivable: $160,000; Credit sales: $1,200,000; Days in the period: 365; Your payment terms: 30 days.

Results — **Days sales outstanding = 45.6 days**; Days beyond terms = 15.6; Receivables turnover = 8.

## FAQ

**What is a good DSO?**
Under 45 days is often considered good, but compare with your terms and industry.

**How can I reduce DSO?**
Invoice promptly, offer early-payment discounts and follow up on late payers.

**Should I use total or credit sales?**
Credit sales – cash sales have no receivable.

**What formula does the DSO Calculator – Days Sales Outstanding use?**
DSO = average accounts receivable ÷ credit sales × days in the period.


## Sources

- [Corporate Finance Institute – financial ratios](https://corporatefinanceinstitute.com/)