Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Exact age
36 years, 2 months, 0 days
Age in whole years
36
Days until next birthday
304
Total days lived
13,210
Total weeks lived
1,887
Total hours lived
317,040
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter date of birth.
- 2Enter as of date.
- 3Read your exact age on the right — it updates as you type.
- 4Hit Share to keep the scenario or send it to someone.
About this calculator
Counts your exact age accounting for leap years, plus the countdown to your next birthday and total days lived.
Worked example
Using the values the calculator loads with:
Inputs
- Date of birth: 1990-06-15
- As of date: 2026-08-15
Results
- Exact age: 36 years, 2 months, 0 days
- Age in whole years: 36
- Days until next birthday: 304
- Total days lived: 13,210
- Total weeks lived: 1,887
- Total hours lived: 317,040
What each field means
Inputs
- Date of birth
- The reference date for this calculation. Defaults to today unless you change it.
- As of date
- The reference date for this calculation. Defaults to today unless you change it.
Results
- Exact age
- Returned as a plain value and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Age in whole years
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Days until next birthday
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total days lived
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total weeks lived
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total hours lived
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the age calculator work?
Counts your exact age accounting for leap years, plus the countdown to your next birthday and total days lived. The underlying maths is: Age = whole years, months, and days elapsed since the birth date.
What do I need to enter?
2 values: date of birth, and as of date. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the exact age result mean?
It is returned as a plain value and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary.
Who is this tool for?
It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Age Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/age-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/age-calculator" target="_blank" rel="noopener">Age Calculator — RevenueLab</a> (2026).</p>
Source: [Age Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/age-calculator) (2026).