CalcHub — 160+ Free Online Calculators & Converters

Estimate monthly mortgage payments, total interest and payoff.

Calculate monthly payment and total cost of any loan.

Equated Monthly Installment for personal, home or auto loans.

See how savings grow with compounding.

Interest = P × R × T.

Estimate net pay from gross salary with a simple flat tax.

Estimate take-home after taxes and deductions.

Approximate federal income tax using single-filer brackets.

Add sales tax to a subtotal.

Split a bill and calculate the tip.

Return on investment.

Project savings at retirement.

Project 401(k) balance with employer match.

First-year amortization breakdown.

Estimate monthly auto loan payment.

How long to pay off a debt at a fixed monthly payment.

How much interest you'll pay on a card balance.

Monthly savings needed to hit a goal.

Annualized return (CAGR).

Future value of money given inflation.

Units needed to cover fixed costs.

Live exchange rates from open.er-api.com.

Compute the price after a percentage discount.

Add or extract VAT.

Revenue, cost → margin and markup.

Max rent using the 30% rule.

Down payment amount from percentage.

Body Mass Index from height and weight.

Daily calorie needs (Mifflin–St Jeor).

Basal Metabolic Rate.

Estimate body fat from tape measurements.

Ideal body weight (Devine formula).

Split calories into protein/carbs/fat.

Estimated due date from last menstrual period (Naegele).

Estimated ovulation window.

Daily water needs by weight and activity.

Training zones from max HR (220-age).

Pace, time, and distance.

Estimated 1RM (Epley).

Health indicator based on WHR.

Approx calories burned per step count.

Ideal wake times using 90-minute cycles.

Check recommended total pregnancy weight gain range based on pre-pregnancy BMI category.

Estimate body frame size (small, medium, large) using the wrist circumference method.

Check which standard blood pressure category a reading falls into.

Calculate waist-to-height ratio, a simple indicator of central body fat and related health risk.

Estimate a pregnancy due date starting from a known conception date, rather than last period date.

Convert temperature both directions.

Convert meters to feet.

Convert kg to lb.

Convert miles to km.

MPH, KPH, m/s, knots.

sq ft, sq m, acres, hectares.

Liters, gallons, ml, cups.

psi, bar, pascal, atm.

Joules, calories, kWh, BTU.

Convert a time between IANA time zones.

mm, cm, m, km, in, ft, yd, mi.

mg, g, kg, oz, lb, ton.

Celsius, Fahrenheit, Kelvin.

B, KB, MB, GB, TB (binary).

Degrees ↔ radians.

MPG ↔ L/100km.

Exact age in years, months, days.

X% of Y, plus percent change.

Weighted GPA on a 4.0 scale.

Days between two dates.

Countdown to a future date.

Cryptographically random integer.

Strong random password.

Timer that alerts when it hits zero.

Precision stopwatch with lap times.

Instant QR codes for URLs, text or vCards.

Count words, characters, sentences.

Number ↔ Roman numeral.

Final grade from weighted assignments.

Total hours between clock in and out (minus break).

See a meeting time in multiple cities.

Compare two package sizes to find which one is actually the better deal per unit.

Break down an amount of money into the fewest US bills and coins.

Apply the square-root curving method to a raw test score.

Convert weekly work hours into a Full-Time-Equivalent (FTE) fraction.

Add / subtract / multiply / divide fractions.

Solve A:B = C:? proportions.

√x.

(new − old) / old.

Full-featured expression calculator.

Arithmetic mean of a list.

Median and mode of a list.

Sample and population standard deviation.

Solve ax² + bx + c = 0.

Is a number prime?

Least common multiple and greatest common divisor.

aⁿ.

logₐ(x).

Add or multiply two 2×2 matrices.

Binary, octal, decimal, hex.

Calculate the number of combinations (nCr) and permutations (nPr) for a set.

Calculate the probability of exactly k successes in n independent trials (binomial probability).

Calculate the slope and angle of a line between two points.

Calculate resistance and power from voltage and current.

Find the color bands for a given resistor value (4-band standard).

Estimate voltage drop across a copper wire run based on current, length, and gauge.

Find the minimum recommended copper wire gauge for a given current.

Convert torque and RPM into horsepower.

Calculate cement, sand, and aggregate quantities for a target concrete volume and mix ratio.

Calculate the energy stored in a charged capacitor.

Calculate power factor from real power and apparent power.

Calculate gear ratio and speed change from tooth counts.

Estimate how much it costs to run an appliance based on wattage, usage time, and electricity rate.

Estimate daily and monthly energy output from a solar panel system.

Estimate how long a battery will last under a given current draw.

Calculate the decibel difference between two power levels.

Calculate total R-value from insulation material and thickness.

Convert cups to grams for common ingredients.

Scale ingredients up or down.

F ↔ C ↔ Gas mark.

Tsp, tbsp, cup, fl oz.

Roasting time by weight (~20 min/lb at 350°F).

How many servings from a bottle.

Gallons of paint for a room (2 coats).

Tiles needed for an area (+ 10% waste).

Concrete cubic yards for a slab.

Boxes of flooring for a room.

Rolls needed for walls.

L × W square footage.

Squares of shingles (100 sq ft each).

Posts and panels for a fence run.

Cubic yards of mulch or soil.

Estimate the volume and weight of gravel or aggregate needed for an area.

Get a general recommended water heater tank size based on household size.

Calculate board feet of lumber from dimensions and quantity.

Trip cost from distance, MPG and price/gal.

MPG from miles driven and gallons used.

Months to pay off a car loan.

Diameter and circumference from tire spec (e.g. 225/45R17).

Time = distance / speed.

Rough flight time at cruise speed.

Rough days to recover (1 day per time zone).

Estimate a vehicle's value over time using a declining annual depreciation rate.

Split total road trip costs evenly among passengers.

Calculate parking cost from an hourly rate, with an optional daily maximum cap.

Hourly rate to hit an income goal.

Subtotal + tax − discount.

Sell price from cost + markup %.

Sales revenue to cover costs.

Weekly pay with time-and-a-half over 40 hours.

Monthly payment for a business loan.

Calculate sales commission from a sale amount and commission rate.

Estimate typical rest and meal break entitlements based on hours worked in a shift.

Calculate the average recruiting cost per hire.

Calculate employee turnover rate for a given period.

Convert dog years using the modern log formula.

Feline age converter.

US / UK / EU conversion (adult).

Compare area of two round pizzas.

Just for fun — deterministic score from two names.

Days until your next birthday.

Western zodiac from date of birth.

Pythagorean numerology (fun only).

Widmark BAC estimate — informational only.