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Most used tools by our community today.
Calculate your monthly mortgage payment with down payment using our free home loan calculator. Ge...
Add, subtract, or find the difference between times in hours, minutes, and seconds. Supports HH:M...
Calculate your Body Mass Index (BMI), check where you fall on the BMI chart, find your ideal weig...
Use our free compound interest calculator to see how your investments grow over time with daily, ...
A full-featured scientific calculator with trigonometry, logarithms, exponents, roots, factorials...
Use our free percentage calculator to calculate percent of a number, percentage increase, decreas...
Calculate your GPA (Grade Point Average) for high school or college. Supports weighted and unweig...
Convert between different units of measurement including length, weight, temperature, volume, are...
Calculate days between two dates, add or subtract days from a date, find business days excluding ...
Calculate the hours and minutes between two times. Perfect for work hours, payroll calculations, ...
Calculate your exact age in years, months, and days from your date of birth. Find out how old you...
Free online countdown timer with alarm sound, full-screen mode, and event date countdown. Set any...
Calculate the area of any shape instantly. Find area of triangles, circles, rectangles, squares, ...
Calculate the volume and surface area of any 3D shape including cube, sphere, cylinder, cone, pyr...
Solve any triangle by entering sides and angles. Calculate area, perimeter, height, angles, and i...
Calculate the perimeter of any shape including rectangle, square, triangle, circle, parallelogram...
Free circle calculator — enter any one value (radius, diameter, circumference, or area) and ins...
Solve the Pythagorean theorem (a² + b² = c²) instantly. Find the hypotenuse, missing leg, or c...
Use our free loan calculator to calculate your monthly payment, EMI, and total interest for any l...
Convert between 150+ world currencies with live exchange rates. Get real-time forex rates for USD...
Calculate how many calories you should eat per day for weight loss, muscle gain, or maintenance. ...
Calculate your Basal Metabolic Rate (BMR) - the number of calories your body burns at rest. Use m...
Calculate your Total Daily Energy Expenditure (TDEE) to know exactly how many calories you burn e...
Add, subtract, multiply, and divide fractions with ease. Simplify fractions, convert to decimals ...
Calculate standard deviation, variance, and mean from your data set with step-by-step explanation...
Calculate probabilities for any scenario with step-by-step solutions. Supports basic, conditional...
Calculate derivatives of any function with step-by-step solutions. Supports polynomials, trigonom...
Compute definite and indefinite integrals with step-by-step solutions. Enter any expression to fi...
Format, validate, and minify JSON online. Pretty print with customizable indentation, syntax high...
Calculate subnet mask, network address, broadcast address, host range, and usable hosts from any ...
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Engineering
A drawing that says 25 ±0.1 is not asking for 25 mm — it is defining the range a part must land in to be accepted. This guide covers the four tolerance notations you will see on real drawings, what ISO fit codes like 25H7/g6 mean in millimetres, the difference between clearance, transition and interference fits, worst-case vs RSS stack-up, and how to pick a tolerance a workshop can actually hold.
Math
Filling a pool, sizing an aquarium, or ordering heating oil? Tank volume is just the volume of a cylinder or box converted into the capacity units you actually buy in — gallons and litres. This guide covers the formulas for cylindrical and rectangular tanks, the cubic-foot-to-gallon conversions, partially full horizontal tanks, pool and aquarium volume, and the five mistakes that throw the numbers off.
Timer
Adding 45 minutes and 30 minutes isn't 75 — it's 1 hour 15. Time looks like ordinary arithmetic but runs in base 60, and that mismatch is why hours-and-minutes math trips everyone up. This guide breaks down how to add, subtract, and convert time correctly by hand, where the carry and the borrow really go, and the minutes-to-decimal-hours conversion that quietly breaks payroll.
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