The Business Days Calculator is a free tool that helps you calculate business days using the formula Count weekdays (Mon-Fri) between the two dates, excluding weekends. Enter your values above and press Calculate to get working days (mon-fri), weekend days, total days instantly, with a full step-by-step breakdown.
What is the Business Days Calculator?
The business days calculator is a free online tool that helps you calculate business days quickly and accurately. It applies the standard formula Count weekdays (Mon-Fri) between the two dates, excluding weekends to the values you enter and, when you press Calculate, displays the result together with a clear, step-by-step explanation of how the answer was reached.
Also known as: business day calculator, working days calculator.
How to use the Business Days Calculator
- Enter the start date.
- Enter the end date.
- See the number of working days.
Formula used
The business days calculator is based on this formula:
Count weekdays (Mon-Fri) between the two dates, excluding weekendsEach term in the formula corresponds to one of the inputs explained below. The calculator performs the arithmetic for you and shows every step so you can check the working by hand if you wish.
Worked example
Suppose you enter 1 Jun to 30 Jun. The calculator works as follows:
| Inputs | 1 Jun to 30 Jun |
|---|---|
| Working | exclude Sat/Sun |
| Result | about 21 working days |
Step-by-step calculation
- Apply the formula:
Count weekdays (Mon-Fri) between the two dates, excluding weekends - Substitute your values: exclude Sat/Sun
- Read the result: about 21 working days
Inputs explained
- Start date — the start date used in the calculation.
- End date — the end date used in the calculation.
Understanding your result
- Working days (Mon-Fri) — the calculated working days (mon-fri).
- Weekend days — the calculated weekend days.
- Total days — the calculated total days.
Benefits and practical uses
The business days calculator saves time and removes the risk of manual errors when you need to calculate business days. It is useful for students, professionals and anyone who wants a fast, dependable answer. Results update the moment you press Calculate, work on any device, and can be copied or shared in a single click — and because the maths runs in your browser, your figures stay completely private.
Tips for an accurate result
- Keep all related inputs in the same units.
- Use the worked example above to confirm you are entering values in the right places.
- Review the assumptions below so the result fits your situation.
- Press Reset to clear everything and try a different scenario.
Common mistakes to avoid
- Entering values in the wrong unit (mismatched units give wrong answers).
- Leaving a required field empty — the calculator will ask you to fill it in.
- Rounding inputs too early, which can slightly change the result.
Assumptions and limitations
- Saturday and Sunday are weekends.
Frequently asked questions
Does this exclude public holidays?
No - it excludes only weekends. Subtract any holidays manually.
How do I use the Business Days Calculator?
Enter your values in the fields, then press the Calculate button to see the result. Use Reset to clear the form and start again. Nothing is calculated until you click Calculate.
What formula does the Business Days Calculator use?
It uses the standard formula: Count weekdays (Mon-Fri) between the two dates, excluding weekends. The full step-by-step working is shown with every result so you can verify it.
What information do I need to use the business days calculator?
You need: start date, end date. Sensible example values are pre-filled so you can see how it works.
Is the Business Days Calculator free to use?
Yes. Every DigiToolkit calculator is completely free, with no sign-up, no login and no usage limits.
Does the Business Days Calculator work on mobile phones?
Yes. The calculator is mobile-first and works on phones, tablets and computers in any modern browser.
Do I need to install an app?
No. The business days calculator runs directly in your web browser — there is nothing to download or install.
Is my data private when I use this calculator?
Yes. All calculations run inside your browser. The numbers you enter are never uploaded to a server or shared with anyone.
How accurate is the Business Days Calculator?
It uses the generally accepted formula for business days and computes to several decimal places. Results are accurate for the assumptions listed on this page.
Can I copy or share my result?
Yes. After calculating, use the Copy button to copy the result, or Share to copy the page link.
Why is nothing showing until I press Calculate?
By design, the calculator only computes when you press Calculate, so you can finish entering all your values first. Press Reset any time to clear everything.