# CalculateFox

> Browser-only calculators with published formulas, worked examples and primary sources, in English, Turkish, German, Portuguese (Brazil), Italian and Spanish (Mexico). No accounts, no uploads, nothing calculated on a server.

Every calculator runs in the reader's browser and each page reads without JavaScript. A tool page carries the formula, a worked example in the market's number format, three or more FAQs, an explicit list of what the tool does not do, and the primary sources it was checked against. Health pages apply published formulas only: they do not interpret a result or give individual advice.

Last updated: 2026-10-31

Other languages: [Türkçe](https://calculatefox.com/tr/llms.txt) · [Deutsch](https://calculatefox.com/de/llms.txt) · [Português](https://calculatefox.com/pt-br/llms.txt) · [Italiano](https://calculatefox.com/it/llms.txt) · [Español](https://calculatefox.com/es/llms.txt)

## Everyday

- [Age calculator](https://calculatefox.com/everyday/age-calculator/): Your exact age in years, months and days — and how long until your next birthday.
- [Days between dates](https://calculatefox.com/everyday/days-between-dates/): The exact number of days between two dates, and how many of them are working days.
- [Percentage calculator](https://calculatefox.com/everyday/percentage-calculator/): Three percentage questions, answered without guessing which formula applies.
- [Hours calculator](https://calculatefox.com/everyday/hours-calculator/): Hours worked between two clock times, minus breaks, in decimal and h:mm.
- [Discount & sales tax calculator](https://calculatefox.com/everyday/discount-and-sales-tax/): The sale price, the tax added, or the net price hidden inside a gross one.
- [Fuel cost calculator](https://calculatefox.com/everyday/fuel-cost-calculator/): What the trip costs, what each passenger owes, and how much fuel it burns.
- [Ratio calculator](https://calculatefox.com/everyday/ratio-calculator/): Find the missing term in a proportion, or reduce a ratio to its simplest form.

## Health

- [Pregnancy due date calculator](https://calculatefox.com/health/pregnancy-due-date/): An estimated due date from your last period, with the current week and trimester.
- [Ovulation calculator](https://calculatefox.com/health/ovulation-calculator/): An estimated ovulation day and fertile window from your last period.
- [TDEE calculator](https://calculatefox.com/health/tdee-calculator/): Your resting burn and daily calorie estimate, with the activity factor shown.
- [BMI calculator](https://calculatefox.com/health/bmi-calculator/): Your BMI, the WHO category, and the healthy weight range for your height.
- [Body fat calculator](https://calculatefox.com/health/body-fat-calculator/): An estimated body-fat percentage from tape measurements, with its error margin.
- [Sleep calculator](https://calculatefox.com/health/sleep-calculator/): Bedtimes that fit whole 90-minute cycles before your alarm.
- [Water intake calculator](https://calculatefox.com/health/water-intake-calculator/): A rough daily fluid estimate from your weight and exercise time.
- [One rep max calculator](https://calculatefox.com/health/one-rep-max-calculator/): An estimated 1RM from a weight and rep count you already lifted.

## Hubs

- [Everyday](https://calculatefox.com/everyday/): Dates, time and numbers you check every week.
- [Health](https://calculatefox.com/health/): Pregnancy, body and fitness numbers, with sources on every page.

## Reference

- [About CalculateFox](https://calculatefox.com/about/): Who runs CalculateFox, why the calculators are free, how the site is funded, and what it deliberately does not do.
- [How we calculate](https://calculatefox.com/how-we-calculate/): The formulas behind each calculator, how dates and rounding are handled, what the tests cover, and what the site deliberately leaves out.
- [Editorial policy](https://calculatefox.com/editorial-policy/): How CalculateFox pages are written and reviewed, how automation is used, how corrections work, and why advertising never influences a calculation.
- [Privacy](https://calculatefox.com/privacy/): What CalculateFox does and does not collect, what the server sees, which analytics run, and what changes when advertising is switched on.
- [Contact](https://calculatefox.com/contact/): How to reach CalculateFox about a wrong result, a broken calculator, a privacy question or a correction.

## Optional

- [Every calculator page above as one Markdown file](https://calculatefox.com/llms-full.txt)