All Calculators
Start with a calculator, then review the formula, examples, FAQ, and related tools.
BMI Calculator
Calculate body mass index from height and weight.
Loan Payment Calculator
Estimate monthly loan payments, total payment, and total interest.
Percentage Calculator
Find a percentage of a number and compare increase or decrease.
Unit Price Calculator
Compare prices by calculating cost per unit.
Compound Interest Calculator
Estimate future value and interest earned over time.
Mortgage Calculator
Estimate mortgage principal, interest, and monthly housing costs.
Tip Calculator
Calculate tip amount, total bill, and split cost per person.
Discount Calculator
Calculate sale price, discount amount, and optional tax.
Sales Tax Calculator
Calculate tax amount and total price after tax.
Savings Goal Calculator
Estimate how long it takes to reach a savings goal.
Calorie Calculator
Estimate BMR, maintenance calories, and a simple weight-loss target.
Body Fat Calculator
Estimate body fat percentage using circumference measurements.
Pace Calculator
Calculate running pace, total minutes, and speed.
Age Calculator
Calculate age in years, months, and total months.
Date Difference Calculator
Calculate days, weeks, and approximate months between two dates.
Time Duration Calculator
Calculate elapsed time between two 24-hour times.
Length Converter
Convert between common length and distance units.
Weight Converter
Convert between grams, kilograms, ounces, pounds, and tons.
Temperature Converter
Convert Celsius, Fahrenheit, and Kelvin.
Fuel Cost Calculator
Estimate fuel needed, trip cost, and cost per mile.
Basic Calculator
Evaluate a quick arithmetic expression.
One-Line Expression Calculator
Run a single-line calculation with parentheses and functions.
Calculation Notebook
Paste a list of numbers and summarize the count, total, average, minimum, and maximum.
Engineering Calculator
Evaluate engineering-style expressions with square root, power, and trigonometric functions.
Scientific Calculator With History
Run a scientific expression for quick constants and function checks.
Tax-Inclusive Price Calculator
Calculate tax amount and tax-inclusive total from a pre-tax price.
Number Base Converter
Convert a whole decimal number to another base from 2 to 36.
Profit Margin Calculator
Calculate gross profit, margin, and markup.
Cycle Calculator
Estimate the next cycle date from a start date and cycle length.
Cycle-Based Fitness Planner
Estimate a planning date from a cycle start and an editable day offset.
Cycle-Based Wellness Planner
Estimate a wellness planning date from a cycle start and an editable day offset.
Mood Check Tool
Summarize simple 1-10 mood scores from a day or week.
Pregnancy Date Calculator
Estimate a due date from a last-period date using an editable day offset.
Pregnancy Weight Calculator
Compare current pregnancy weight gain with an editable target range.
Conception Date Calculator
Estimate a conception date from a due date with an editable offset.
Baby Age In Days Calculator
Count calendar days and weekdays between birth date and another date.
Premature Baby Corrected Age Calculator
Estimate corrected age in weeks from chronological age and weeks early.
28-Day Cycle Care Planner
Plan a 28-day cycle milestone from a start date and editable offset.
Body Shape Calculator
Estimate waist-to-hip and waist-to-height ratios.
Baby Formula Temperature Calculator
Estimate mixed-water temperature from hot and cool water amounts.
Public Holiday Calendar Helper
Count weekdays across a date range and subtract known holidays.
Insurance Age Calculator
Estimate insurance age by adding an editable rounding adjustment to actual age.
Date Add/Subtract Calculator
Add or subtract days and months from a date.
Workday Calculator
Estimate workdays between two dates with an editable holiday count.
Day Counter
Count calendar days and weekdays across a date range.
Kids Timer
Plan a simple child-friendly timer cycle.
Height Match Calculator
Compare two heights and calculate their difference and ratio.
Target Heart Rate Calculator
Estimate maximum heart rate and training zone from age and intensity.
Exercise Calories Calculator
Estimate calories burned from MET, weight, and duration.
Shoe Size Converter
Estimate common shoe size conversions from foot length.
Currency Converter
Convert an amount using an editable exchange rate and fee.
Travel Exchange Rate Calculator
Estimate travel money after exchange spread and card fee.
TV Viewing Distance Calculator
Estimate viewing distance from screen size.
Color Count Tool
Paste color values or labels and count entries, words, and lines.
Screen PPI Calculator
Calculate pixels per inch from resolution and diagonal size.
PPM Concentration Converter
Convert ppm to percent and decimal concentration.
Chinese Text Utility
Paste Chinese text and count characters, non-space characters, words, and lines.
Taiwan Taxi Fare Calculator
Estimate a taxi fare from editable local fare assumptions.
Hong Kong Taxi Fare Calculator
Estimate a taxi fare from editable Hong Kong fare assumptions.
Time Speed Distance Calculator
Calculate speed and pace from distance and time.
Gear Ratio RPM Calculator
Estimate wheel RPM from engine RPM and gear ratio.
Tire Size Upgrade Calculator
Compare tire diameter from width, aspect ratio, and rim size.
Fuel Price Change Calculator
Estimate how a fuel price change affects a refill.
Electricity Bill Calculator
Estimate electricity cost from kWh and an editable rate.
Word Count Tool
Count words, characters, non-space characters, and lines.
Air Conditioner BTU Calculator
Estimate cooling capacity from room area and BTU per square foot.
Air Conditioner Electricity Cost Calculator
Estimate air conditioner electricity use and cost.
Golden Ratio Calculator
Scale a value by the golden ratio and its reciprocal.
Credit Card Debt Calculator
Estimate months to pay off credit card debt with fixed monthly payments.
Car Purchase Budget Calculator
Estimate an out-the-door car budget with taxes and fees.
Weekly Savings Challenge Calculator
Estimate savings from a weekly increasing challenge.
Bicycle Gear Calculator
Estimate bicycle gear ratio and gear inches.
Random Draw Tool
Pick one or more entries from a list using a deterministic seed.
Map Distance Calculator
Estimate travel time from distance and average speed.
Aquarium Volume Calculator
Calculate aquarium volume from length, width, and height.
Water Intake Calculator
Estimate daily water intake from body weight.
Cup Volume Calculator
Estimate cylindrical cup volume.
Waist-To-Hip Ratio Calculator
Calculate waist-to-hip ratio from body measurements.
Mortgage Refinance Calculator
Estimate simple monthly savings and break-even months for refinancing.
Mortgage Grace Period Calculator
Estimate interest accrued during a grace period.
Rotating Savings Bid Calculator
Estimate simple bid interest from group savings assumptions.
Stock Limit-Up/Limit-Down Calculator
Estimate upper and lower price limits from an editable percentage rule.
Stock Profit/Loss Calculator
Calculate stock trade profit or loss before detailed broker rules.
Stock Ex-Dividend Calculator
Estimate adjusted price after cash and stock dividends.
Baseball ERA Calculator
Calculate earned run average.
Baseball Batting Average Calculator
Calculate batting average from hits and at-bats.
Running Calories Calculator
Estimate running calories from weight and distance.
Blood Alcohol Calculator
Estimate BAC with editable drink, body-water, and metabolism assumptions.
Buy Vs. Rent Calculator
Compare simple monthly owning and renting costs.
Interval Timer
Plan active/rest interval rounds.
Stopwatch Session Calculator
Plan repeated timed stopwatch attempts.
Millisecond Stopwatch Planner
Convert short timed attempts into a total session duration.
Dog Age Calculator
Estimate dog age in human-year equivalents with editable multipliers.
Dog Pregnancy Due Date Calculator
Estimate a dog pregnancy due date from breeding date.
Cat Age Calculator
Estimate cat age in human-year equivalents with editable factors.
Cat Pregnancy Due Date Calculator
Estimate a cat pregnancy due date from breeding date.
Ratio Calculator
Calculate ratio, scaled values, and proportional parts.
Tally Counter
Calculate the next counter value from a current value and step.
Smoking Cost Calculator
Estimate smoking cost over days, months, and years.
Alcohol Spending Calculator
Estimate drinking or beverage spending over a month.
Countdown Alarm Planner
Plan a countdown alarm length.
Visual Countdown Alarm Planner
Plan a visual countdown alarm sequence.
Cuckoo Clock Planner
Estimate a repeated chime schedule length.
Pomodoro Timer
Plan Pomodoro work and break rounds.
YouTube Alarm Planner
Paste video links or alarm notes and count entries for a playlist alarm.
Multi-YouTube Player Planner
Paste multiple video links and count lines for a multi-video setup.
Perpetual Calendar With Notes
Draft calendar notes and count words, characters, and lines.
Tile Area Calculator
Estimate tile count from room area, tile size, and waste percentage.
Sleep Cycle Calculator
Estimate sleep duration from sleep cycles and minutes per cycle.
Sunrise/Sunset Daylight Calculator
Estimate daylight duration from sunrise and sunset times entered as decimal hours.
Real Promotion Discount Calculator
Estimate the real discount from buy-more-save-more promotions.
365 Savings Plan Calculator
Estimate total savings from a daily increasing savings plan.
Child Height Prediction Calculator
Estimate child adult height from parent heights with an editable offset.
Parking Fee Calculator
Estimate parking fee from duration, free minutes, hourly rate, and cap.
Hidden Cash Calculator
Add up small hidden cash amounts from multiple places.
Electric Vehicle Charging Cost Calculator
Estimate EV charging cost and range added.
Camera Distance Calculator
Estimate camera distance from subject height, focal length, and sensor height.
Depth Of Field Calculator
Estimate hyperfocal distance from focal length, aperture, and circle of confusion.
Reaction Test Score Calculator
Summarize reaction test attempts from average milliseconds.
Effective Annual Rate Calculator
Estimate effective annual rate from interest paid and loan principal.
Microwave Heating Time Calculator
Scale microwave heating time between wattages.
Power Bank Wh Calculator
Convert battery mAh and voltage to watt-hours.
Shipping Cost Comparison Calculator
Compare two shipping methods by base fee and weight fee.
Markup Calculator
Calculate selling price, markup amount, and margin from cost and target markup.
Markup Vs Margin Calculator
Compare markup and margin from cost and selling price.
Break-Even Calculator
Estimate break-even units and revenue from fixed cost and unit economics.
Pricing Calculator
Estimate a selling price from cost and target margin.
Hourly To Salary Calculator
Convert hourly pay to weekly, monthly, and annual salary.
Overtime Calculator
Estimate overtime pay from base rate, extra hours, and overtime multiplier.
Commission Calculator
Estimate commission payout from sales, rate, and optional base pay.
Freelance Rate Calculator
Estimate an hourly and project rate from income goals, costs, taxes, and billable hours.
Take-Home Pay Calculator
Estimate take-home pay after tax and other deductions.
ROAS Calculator
Measure return on ad spend and revenue left after ad cost.
ROI Calculator
Calculate return on investment from gain and cost.
CPM Calculator
Estimate cost per thousand impressions from spend and impressions.
CPC Calculator
Estimate cost per click from total spend and click volume.
Etsy Fee Calculator
Estimate marketplace fees, net proceeds, and profit for an Etsy-style order.
Shopify Profit Calculator
Estimate ecommerce order profit after product cost, shipping, fees, and ad spend.
Concrete Cost Calculator
Estimate concrete volume, bag count, and cost from slab dimensions.
Gravel Calculator
Estimate gravel volume, tonnage, and material cost.
Paint Calculator
Estimate gallons to buy and total paint cost from wall area, coats, and waste.
Square Footage Calculator
Calculate area in square feet and square meters from length and width.
Flooring Calculator
Estimate flooring boxes and project cost from room area, box coverage, and waste factor.