Everyday calculators, beautifully simple
Mortgages, loans, BMI, calories, percentages, and unit converters — fast tools with clear answers. No signup. No clutter.
FinanceView all
Loan / EMI Calculator
Monthly payment, total interest, and payment count for fixed-rate loans.
Open tool →Mortgage Calculator
Estimate monthly principal and interest for a fixed-rate home loan.
Open tool →Interest Calculator
Simple vs compound interest growth over time.
Open tool →Savings Goal Calculator
How much to save monthly to reach a goal with compound interest.
Open tool →Discount Calculator
Sale price and amount saved from original price and discount %.
Open tool →Tip Calculator
Split the bill and calculate tip percentage.
Open tool →ROI Calculator
Return on investment percentage and profit.
Open tool →HealthView all
BMI Calculator
Body mass index with WHO adult categories.
Open tool →Calorie / TDEE Calculator
Mifflin-St Jeor BMR and daily energy estimate.
Open tool →Water Intake Calculator
Simple daily water intake estimate from weight and activity.
Open tool →Ideal Weight Calculator
Devine formula ideal body weight estimate.
Open tool →Math and datesView all
Percentage Calculator
Percent of, percent change, and X is what % of Y.
Open tool →Average Calculator
Mean of a list of numbers (comma or space separated).
Open tool →Ratio Calculator
Simplify ratios and scale proportionally.
Open tool →Age Calculator
Exact age in years, months, and days.
Open tool →Date Difference Calculator
Days between two dates.
Open tool →ConvertersView all
Length Converter
Convert m, cm, mm, km, in, ft, yd, mi.
Open tool →Weight Converter
Convert kg, g, lb, oz, stone.
Open tool →Temperature Converter
Celsius, Fahrenheit, and Kelvin.
Open tool →Speed Converter
mph, km/h, m/s, knots.
Open tool →Area Converter
m2, ft2, acres, hectares, yd2.
Open tool →Data Storage Converter
KB, MB, GB, TB (decimal SI).
Open tool →Guides & explainersAll guides
How Mortgage Payments Are Calculated
The amortisation formula, interest/principal split, and what the payment leaves out.
Read guide →What BMI Gets Wrong
Where the standard bands mislabel you — and the measurements that do better.
Read guide →TDEE Explained
BMR vs TDEE, honest activity multipliers, and using the number to lose or gain.
Read guide →Discount Math Done Right
Why stacked percentages multiply, and how to compare offers without being framed.
Read guide →How CalcDesk calculates — our methodology
Every tool on CalcDesk runs the standard, published formula for its task — the amortisation equation lenders use, the WHO BMI bands, the Mifflin-St Jeor energy equation, and exact SI/international unit definitions. Nothing is approximated behind the scenes, no inputs are sent anywhere: all math executes locally in your browser.
We label every result's assumptions plainly (principal-and-interest only, population-scale screening bands, decimal storage units) and each calculator page includes the full formula, a worked example, common mistakes and an FAQ written by our editors — no scraped text, no filler. If a figure matters financially or medically, treat our result as a fast estimate and verify with a qualified professional; every page says so, and our About page explains who maintains these tools and why.