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Free Online Calculators for Everyday Decisions
Daily Calculator gives you 230+ fast, accurate tools for maths, money, health, dates, unit conversion, engineering and computing — all running entirely inside your browser. No signup, no ads, no data collection.
Recently used
Stored only in your browser.
Most Popular Calculators
Quick access to the tools our visitors use most often across the whole library.
Percentage Calculator
Find a percent of a number, what percent one value is of another, and percentage change.
Basic Calculator
Simple on-screen keypad for addition, subtraction, multiplication and division.
Mortgage Calculator
Estimate monthly payments, total interest and a full amortization schedule.
Loan Calculator
Work out monthly payments, total interest and repayment time for any loan.
Compound Interest
See how investments grow with monthly contributions and compounding.
BMI Calculator
Calculate body mass index in metric or imperial units with WHO categories.
Calorie Calculator
Estimate daily calorie needs for weight loss, maintenance or muscle gain.
Age Calculator
Find your exact age in years, months, weeks and days from any birth date.
Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin and Rankine instantly.
Square Footage Calculator
Calculate square footage for rooms, floors, walls and irregular shapes.
Standard Deviation
Compute sample and population standard deviation with mean and variance.
Length Converter
Convert between metres, feet, inches, miles, kilometres and more.
Browse Calculators by Category
Every tool is organised so you can find the right calculator in a couple of taps.
Math
Arithmetic, percentages, fractions, statistics, probability and algebra helpers.
Geometry
Shapes, area, volume, surface area plus concrete, paint, tile and flooring estimators.
Finance
Mortgages, loans, interest, savings, retirement, salaries, taxes and everyday money.
Health & Fitness
BMI, BMR, calories, macros, body fat, running pace, heart rate and pregnancy dates.
Date & Time
Age, date differences, business days, week numbers, time zones and Unix timestamps.
Unit Converters
Length, weight, temperature, volume, speed, pressure, energy, data and cooking units.
Engineering
Ohm's law, voltage drop, BTU, horsepower, gear ratio, molarity and thermodynamics.
Computing
IP subnetting, binary conversion, Base64, URL encoding, passwords, GPA and grades.
Featured Calculators This Week
Hand-picked tools that solve tricky problems well — perfect if you have a specific calculation in mind.
Mortgage Amortization
See a full year-by-year breakdown of principal versus interest across the life of your mortgage.
Confidence Interval
Compute 90%, 95% and 99% confidence intervals for a sample mean using the z-distribution.
Macronutrient Split
Split daily calories into protein, carbohydrate and fat targets based on your goal.
Business Days Calculator
Count working days between two dates, excluding weekends and any custom holidays.
Data Storage Converter
Convert between bytes, kilobytes, megabytes, gigabytes and binary equivalents.
IP Subnet Calculator
Compute network address, broadcast, host range and subnet mask from any CIDR block.
Why People Choose Daily Calculator
A calculator site should get out of your way and give you an answer. Here's how we try to do that.
Privacy-respecting
Calculations run in your browser. Your numeric inputs are never transmitted to any server for processing.
Transparent formulas
Each calculator explains the formula it uses, defines every variable and shows at least one worked example.
Unit-tested maths
Formula modules are covered by automated tests with known inputs and expected outputs, so bugs are caught quickly.
Real amortization & tables
Where a table is more useful than a single number — loans, statistics, conversions — we render the full detail.
Works on every device
A single responsive layout that reads clearly on a 320 px Android phone and a 4K desktop monitor alike.
Calculation Guides
Short, practical explanations of the maths behind the tools — so you can double-check any answer and understand what the result really means.
Math
How Percentages Work
Percent of a number, percentage change, percentage difference — explained with clear examples.
Read guide FinanceHow Compound Interest Works
Compounding frequency, the compound interest formula and why time matters more than rate.
Read guide FinanceHow to Calculate Loan Payments
The amortized payment formula step by step, plus how principal, rate and term interact.
Read guide HealthHow to Calculate BMI
The BMI formula, WHO categories and the limitations you should know before relying on it.
Read guide ConvertersHow to Convert Temperature Units
Exact Celsius, Fahrenheit, Kelvin and Rankine conversions and why temperature is special.
Read guide MathHow to Calculate Averages
Mean, median, mode and weighted average — and how to pick the right one for your data.
Read guideAbout Daily Calculator
Daily Calculator is an independent project built for one purpose: to make accurate, everyday calculations easy to find and easy to trust. Instead of burying a single generic tool behind dozens of tabs, we publish a dedicated page for each calculator so a link can point directly at the exact tool someone needs.
The whole site is a static, client-side web application. Every calculation runs locally in your browser — there is no backend service receiving your inputs, no account system and no advertising pixel tracking your activity across sites. Where a tool needs to remember a preference (such as your recently used calculators or your colour-scheme choice) we store it in your browser's local storage, and only your browser can read it.
The calculator library covers the areas people ask about most: maths and statistics, geometry and construction, personal and business finance, health and fitness, dates and times, unit conversions, engineering and computing. Each tool is accompanied by an explanation of the formula used, at least one worked example, common mistakes to avoid and links to closely related calculators.
We aim to write real content rather than filler. That means when a formula has a caveat, we say so. When a financial projection depends on jurisdiction, we say so. When a health estimate is a screening tool rather than a diagnosis, we say so.
Daily Calculator is provided as-is for general information. Results are estimates, not professional advice. See our Terms and Privacy Policy for details.
Frequently Asked Questions
Yes. Every calculator and converter is completely free. There is no sign-up, no account requirement, no subscription and no paywall. Use any tool as often as you like.
No installation is required. Daily Calculator runs entirely in your browser on any modern desktop or mobile device. Open a page and start calculating.
All calculations run locally in your browser. Your numeric inputs are not transmitted to any server. Features that need local storage — such as your recently used calculators list — save small preferences in your browser only.
Over 230 free calculators and converters spanning mathematics, geometry, finance, health, date and time, unit conversion, engineering and computing.
Yes. Every page is mobile-first and works on small Android and iOS devices as well as tablets and desktop monitors. Layouts, forms and result panels adapt automatically to your screen size.
No. Financial and tax calculations use general formulas and simplified assumptions. Tax law differs by country and region, so results should be treated as estimates only. Consult a qualified financial or tax professional for advice specific to your situation.
No. Health tools such as BMI, BMR and calorie calculators are educational estimators. They do not diagnose conditions and are not personalised medical advice. Speak to a healthcare professional for guidance about your health.
Use the search box at the top of any page, or browse by category from the main navigation. A full list of every tool is available on the sitemap page.
Use the contact page to send a message. Feedback about incorrect results, unclear wording or missing tools is welcome and helps improve the site.
Daily Calculator does not use third-party advertising cookies. Any optional analytics are privacy-first, non-identifying and disabled by default unless a site operator explicitly enables them.
Browse All Calculators
Looking for something specific? The sitemap lists every calculator grouped by category.