Free calculator widgets for your website

Calculate monthly mortgage payments including taxes and insurance

Calculate monthly payments for personal, auto, or business loans

See how compound interest grows your savings over time

Calculate tip amount and split the bill between multiple people

Estimate your monthly auto loan payment with trade-in and tax

Calculate simple interest using SI = P × r × t

Find out how much to save each month to reach your goal

Calculate sale prices, discount percentages, and original prices

Plan your monthly budget using the 50/30/20 rule

Compare avalanche vs. snowball strategies to pay off debt faster

Calculate how much emergency savings you need and when you'll reach it

See your payoff date and total interest cost for any credit card

Calculate student loan payments and compare repayment plans

Calculate time-and-a-half, double time, and annual overtime earnings

Add tax, reverse it out of a total, or find the rate — with 2026 state rates

Clock in/out times to total hours, overtime split, and pay

Monthly payment and a full month-by-month amortization schedule for any loan

How much sooner you pay off your mortgage, and the interest you save, with extra payments

Tax-free Roth IRA growth to retirement, with 2026 contribution limits and income phase-out

Monthly payment, amount financed, and total interest on a boat loan

Monthly payment, amount financed, and total interest on an RV or camper loan

Compare two loan offers by payment, total cost, and APR

Years to double your money — the shortcut plus the exact answer

Live exchange rates for 30 major currencies (European Central Bank)

Exchange rates on any past date back to 1999 (ECB data)

Live Bitcoin and crypto prices — convert coins to fiat or each other

Live unrealized profit/loss, ROI, and break-even on a crypto position

Average cost per share, break-even, and gain across purchases

Net college cost after scholarships, grants, and family funds

Project a 529 college fund and the monthly savings to reach a goal

Assets minus debts, with home equity, liquid net worth, and allocation

Your FI number, years to financial independence, and Coast FI threshold

Projected college cost with inflation and your 529 savings coverage

Debt-to-income ratios scored against 28/36, FHA, VA, and conventional limits

Certificate of deposit growth at any APY, with early-withdrawal penalty math

Dollar value between any two years (1913–2025) with official BLS CPI data

How much house you can afford using the 28/36 rule with the full payment breakdown

Monthly savings, break-even month, and lifetime savings for any refinance

Convert between hourly, weekly, monthly, and annual pay in both directions

Project 401(k) growth with employer matching and 2026 IRS limits

Project your nest egg and see how much more to save for your income goal

Hourly or salary to net paycheck with 2026 federal tax brackets and FICA

Estimate your defined-benefit pension from years, multiplier, and final average salary

Budget your housing allowance and see the tax-free value of BAH

Overtime pay with night, weekend, and charge differentials included

Basal metabolic rate (calories at rest) via Mifflin-St Jeor

Total daily energy expenditure and calorie targets by activity level

Estimate blood alcohol content (Widmark) — an estimate, never for driving

Convert A1C to estimated average glucose (eAG) and back

Estimate lean (fat-free) mass and fat mass (Boer formula)

Waist ÷ height health-risk ratio — a simple BMI alternative

Classify a reading with AHA categories (normal to crisis)

Estimate cardio fitness (VO₂ max) from resting heart rate

Convert drink volume and ABV into UK units and US standard drinks

Total:HDL ratio and non-HDL cholesterol heart-health markers

WHR and WHO cardiovascular risk classification for men and women

1RM from any set (Epley & Brzycki) with 65-95% training loads

Estimated ovulation date and fertile window from your cycle

Daily protein target by body weight and goal, with per-meal breakdown

Body surface area by Mosteller and Du Bois, with mg/m² dose math

Estimate body fat percentage with the US Navy tape-measure method

Calories burned for 25 activities using Compendium MET values

Solve running pace, time, or distance with race-time projections

Ideal bedtimes and wake-up times on 90-minute sleep cycles

Calculate your Body Mass Index and understand your weight category

Calculate daily calorie needs (BMR & TDEE) using Mifflin-St Jeor

Find your ideal weight using four clinical formulas (Devine, Hamwi, Robinson, Miller)

Calculate your due date using LMP, conception date, IVF transfer, or ultrasound

Find your 5 training heart rate zones using the Karvonen method

Calculate drug dosage volumes, weight-based doses, and IV drip rates

Calculate gtt/min, mL/hr flow rate, and infusion time with any drop factor

Convert mcg/mg/g, mL/tsp/tbsp, lb/kg, °C/°F, and electrolyte mg ↔ mEq

Calculate protein, carbs, and fat macros based on calories and diet style

Calculate daily water needs based on weight, activity, and climate

Find your 5 heart rate training zones using max heart rate

Convert time between world zones with automatic daylight saving

Convert between 12-hour and 24-hour (military) time

Convert numbers to Roman numerals and back, from 1 to 3,999

Perimeter of a rectangle, square, triangle, or circle circumference

Percentage, letter grade, and how many you can miss for a target

How many hours a day to study before an exam, and if it's realistic

Convert a word count into reading or speaking time at any pace

Count words, characters, sentences, and paragraphs with reading time

Count characters with and without spaces, plus platform limits

Count down the days, weeks, and months from today to any date

Create strong random passwords in your browser with a strength meter

Generate random numbers in any range, with no-repeat and sort options

Sample and population standard deviation, variance, and mean from data

Convert kilograms to pounds and back — 1 kg = 2.20462 lbs

Convert centimeters to inches and back — 1 cm = 0.3937 in

Convert °C to °F and back — °F = °C × 9/5 + 32

Convert centimeters to feet and back — ideal for height

Convert miles per hour to km/h and back — 1 mph = 1.60934 km/h

Convert kilometers to miles and back — 1 km = 0.621371 miles

Convert milliliters to US fluid ounces and back — 1 fl oz = 29.5735 ml

Convert grams to ounces and back — 1 oz = 28.3495 g

Solve ax²+bx+c=0 — roots, discriminant, and vertex

Slope, line equation, distance, and midpoint from two points

Least common multiple and greatest common divisor (GCF/HCF)

Raise any base to any power, including negative and fractional

log base b, natural log (ln), log₁₀, and log₂

Square root, cube root, or nth root with simplified radical

Prime factors, primality check, and all divisors of a number

Convert numbers to scientific, E, and engineering notation

Convert meters to feet and back — 1 m = 3.28084 ft

Convert liters to US gallons and back — 1 gal = 3.78541 L

Convert stone to pounds and back — 1 stone = 14 lbs

Convert inches to feet and back — 12 in = 1 ft

Convert pounds to ounces and back — 1 lb = 16 oz

Convert US cups to milliliters and back — 1 cup = 236.588 ml

Convert sq ft to sq m and back — 1 sq ft = 0.0929 sq m

Convert acres to square feet and back — 1 acre = 43,560 sq ft

Exact age in years, months, and days — with totals and birthday countdown

Days between dates (with business days) or add days to any date

Add, subtract, multiply, and divide fractions with automatic simplification

Mean, median, mode, range, and sum from any list of numbers

Simplify ratios, solve proportions, and scale mixtures

Weighted course grade and the score you need on the final

Calculate percentages, percentage change, and percentage increases or decreases

Calculate the area of square, rectangle, circle, triangle, and more with unit conversion

Calculate volume of cubes, cylinders, spheres, cones, and more

Calculate mean, median, mode, standard deviation, variance, and more

Solve any triangle using SSS, SAS, or AAS with angles and area

Calculate radius, diameter, area, and circumference from any known value

Convert length, weight, temperature, volume, area, speed, and time units

Full-featured scientific calculator with trig, log, and advanced functions

Add, subtract, and compare time durations and find time differences

Solve for speed, distance, or time using Distance = Speed × Time

Calculate probability, combinations (nCr), and permutations (nPr)

Calculate weighted GPA on the 4.0 scale with letter grades and credit hours

Margin from cost and revenue, equivalent markup, and target-margin pricing

Price from cost and markup, with a markup-to-margin reference table

Flat or tiered commissions with splits and base salary

Simple and annualized return on investment with all costs included

Calculate units and revenue needed to break even. Find your contribution margin and margin of safety.

Calculate your freelance or consulting hourly rate, day rate, and project quotes

Calculate photography session pricing including editing, travel, and rights

Estimate web design project costs by type, pages, and complexity

Estimate legal fees by practice area and billing type

Calculate construction project bids with materials, labor, and overhead

Analyze restaurant profitability with food cost, labor, and expense ratios

Calculate profit per unit sold with COGS, fees, shipping, and ad spend

Calculate self-employment tax, income tax, and quarterly estimated payments

Penalty-safe 2026 estimated payments with safe harbor rules and due dates

Calculate landscaping project quotes with labor, materials, and profit

Calculate cleaning service pricing by home size, type, and add-ons

Calculate minimum viable rates and project pricing for service businesses

Available home equity credit line, draw and repayment payments

Annual and monthly property tax with average rates for all 50 states

Total area across rooms in sq ft and m², with cost per square foot

Gallons of paint for any room — walls, ceiling, coats, and cost

Material with waste allowance, boxes to buy, and cost

Cubic yards and bags of concrete for a slab, footing, or column

Cubic yards and tons of gravel or stone for any area and depth

Cubic yards and bags of mulch for garden beds at any depth

NOI and capitalization rate for rental property, or value from a target cap

Cash to close at any down payment tier, with PMI thresholds and months to save

Honest year-by-year comparison with equity, appreciation, and opportunity cost

Calculate agent commissions and seller net proceeds

Analyze rental property investment with cash flow, cap rate, and ROI

Calculate gross and net rental yield for any property

Monthly and annual cash flow plus cash-on-cash return for a rental

Calculate fix and flip profit, ROI, and 70% rule check

Split a check evenly with tip among any number of people

Track event spending by category against a total budget

Estimate food, drink, ice, and supplies from your guest count

Plan gift spending per person against a total holiday budget

Roasting time, oven temp, and internal temp by meat and weight

Floor area, volume, AC size, and capacity from room dimensions

Yards of fabric needed, accounting for bolt width and pattern repeat

What any appliance costs to run per day, month, and year

Break down your wedding budget by venue, catering, photography, and more

Estimate total trip costs including flights, hotel, food, and activities

Scale any recipe up or down by changing serving size

Calculate plants, seeds, soil, and fertilizer for your garden

Estimate annual pet care costs for dogs, cats, and other pets

Estimate moving costs for local, long-distance, or DIY moves

Calculate home office tax deduction and setup costs

Price wedding vendor services by type, duration, and experience level

Estimated annual car upkeep from mileage, age, and vehicle type

Rough car insurance premium estimate from your driver profile

Gas cost for any trip, plus weekly, monthly, and annual commute costs

Real gas mileage from a fill-up, with MPG ↔ L/100km conversions

Lease payment from cap cost, residual, and money factor — real dealer math

Project your car's value year by year with adjustable depreciation rates

Budget gas, hotels, food, and activities with a per-person split

System size, cost after incentives, savings, and payback from your bill

Compare electric vs gas fuel cost per year, per mile, and lifetime

Energy, money, and CO2 saved by switching bulbs to LED

Annual household CO2 from energy and travel, broken down by source

Heating savings vs electric resistance, gas, oil, or propane

Cooling energy and cost saved by upgrading to a higher SEER

Backup runtime during an outage and batteries needed for a target

Annual heating cost saved by upgrading a surface's R-value

Daily, monthly, and annual cost of driving to work with wear

DIM weight and billable weight carriers use to price shipments

Estimate NMFC freight class of an LTL shipment from density

Gross pay from cents-per-mile, stops, detention, and per diem

Owner-operator cost per mile, break-even rate, and profit

Annual fleet fuel spend and savings from better MPG

Compare hourly, daily-max, and monthly parking to find the cheapest

Reimbursement at the IRS standard mileage rate or a custom rate

Total production, revenue, profit, and break-even yield for a field

Plants per acre and seed needed from row and plant spacing

Fertilizer product needed to hit a target nutrient rate per acre

Daily and total feed and cost for a herd from body weight

Gallons and acre-feet to apply a water depth over a field, plus cost

Feeder cattle net profit, cost of gain, and break-even price

Bales of hay needed to feed a herd over a season, with waste

Bushel capacity of a round grain bin from diameter and depth