Free online tools
Every tool runs entirely in your browser, with no sign-up and nothing uploaded. Pick a category below or start with one of the popular tools.
Popular tools
- Etsy Fee CalculatorFree Etsy fee calculator: enter your price and see listing fee, 6.5% transaction fee, 3% + $0.2
- Inches to Centimeters ConverterFree inches to cm converter. Type any length in inches and see the exact value in centimeters i
- Roof Pitch CalculatorFree roof pitch calculator. Enter rise and run, a pitch, or an angle to get the X:12 pitch, deg
- How Much to TipFree tip calculator: enter your bill and tip percentage to see the tip, the total and the per-p
- Sleep Cycle CalculatorFree sleep cycle calculator: enter your wake-up time or bedtime for the best times to sleep, ba
- Dog Water Intake CalculatorFree dog water intake calculator: enter your dog's weight, activity and weather to see how many
- Credit Card Payoff CalculatorFree credit card payoff calculator: enter your balance, APR and monthly payment to see how many
- Celsius to Fahrenheit ConverterFree Celsius to Fahrenheit converter. Type °C and get °F instantly (F = C × 9/5 + 32), with a c
- Carpet CalculatorFree carpet calculator: enter your room sizes to get square feet, square yards and roll length,
- Days Between DatesFree days between dates calculator. Pick two dates and get the exact day count, weeks, weekdays
Recently updated
- 17 Months Ago From TodaySee the exact date 17 months ago from today, the weekday it fell on, the 518 day interval in ho
- 16 Weeks Ago From TodaySee the exact date 16 weeks ago from today, the weekday it fell on, the 112 day phase in hours
- 16 Months Ago From TodaySee the exact date 16 months ago from today, the weekday, the 488 day interval in hours and sec
- 15 Weeks Ago From TodaySee the exact date 15 weeks ago from today, the weekday it fell on, the full 105 day phase in h
- 15 Months Ago From TodayPin down the exact date 15 months ago from today, its weekday, the 457 day interval in hours an
- 13 Weeks Ago From TodaySee the exact date 13 weeks ago from today, the weekday it fell on, the 91 day stretch in hours
- 13 Months Ago From TodayPin down the exact date 13 months ago from today, its weekday, the 396 day interval in hours an
- 12 Weeks Ago From TodaySee the exact date 12 weeks ago from today, the weekday it fell on, the 84 day phase in hours a
- 11 Weeks Ago From TodaySee the exact date 11 weeks ago from today, the weekday it landed on, the 77 day span in hours
- 12 Months Ago From TodaySee the exact date 12 months ago from today, the weekday it fell on, the 365 day span in hours
All tools by category
Automotive
- 20/4/10 Rule CalculatorThe 20/4/10 rule: 20% down, a 4 year loan and total car costs under 10
- BMW Monthly Payment CalculatorSee the monthly payment on a new BMW 3 Series, X3 or X5 after tax, dow
- Brake Pad Life CalculatorFree brake pad life calculator: enter your pad thickness, miles driven
- CC to HP CalculatorEstimate horsepower from engine cc with divisors for utility, car, tur
- Capitalized Cost CalculatorWork out gross and adjusted capitalized cost on a car lease, then see
- Car Affordability CalculatorSee how much car you can afford with the 20/4/10 rule: 20% down, a 4-y
Converters
- 12 Hour to 24 Hour Converter CalculatorConvert 12 hour clock times to 24 hour time and back. The 12 AM and 12
- Acres to Hectares ConverterConvert acres to hectares and back with the exact NIST factor: 1 acre
- Acres to Linear Feet CalculatorConvert acres to linear feet and perimeter. A 1-acre square has 208.71
- Acres to Square Feet ConverterConvert acres to square feet and sq ft to acres instantly. 1 acre equa
- Activation Energy CalculatorFind activation energy from two rate constants and temperatures with t
- Air Density CalculatorFind air density from temperature, pressure, humidity or altitude in k
Date Time
- 1 Hour From Now1 hour from now is the same minute on the next hour. See the 12 o'cloc
- 1 Month Notice Period CalculatorEnter the day you hand in notice to get the last day of a one month pe
- 1/8 Mile Time CalculatorTurn an eighth mile ET and trap speed into average speed, acceleration
- 10 Hours From Now10 hours from now is your clock plus ten hours. See the sleep window i
- 10 Minutes Ago10 minutes ago means the clock minus ten minutes, borrowing an hour wh
- 10 Weeks Ago From TodaySee the exact date 10 weeks ago from today, the weekday it landed on,
Design
- Aspect Ratio CalculatorEnter a width and height to get the exact aspect ratio, the decimal fo
- Color Contrast CheckerCheck the contrast ratio between any two colors and see instantly whet
- Color Picker and Contrast CheckerPick a color and read it as HEX, RGB and HSL, then see its contrast ra
- Crop Factor and Equivalent Focal Length CalculatorEnter a lens and a sensor size to get the crop factor, the full-frame
- Hex to RGB ConverterConvert any hex color to RGB, RGBA and HSL in one step. Handles 3, 4,
- Image File Size CalculatorCalculate an image's file size from its pixel dimensions, colour depth
Developer
Ecommerce
- Airbnb Host Fee CalculatorSee what Airbnb takes from a booking: 15.5% single fee or 3% split fee
- Amazon FBA Fee CalculatorEstimate Amazon FBA fees per unit on the 2026 rate card: fulfillment,
- Big Cartel Fee CalculatorAdd your Big Cartel plan fee to card processing and see the real month
- Book Printing Cost CalculatorEstimate book printing cost from page count, trim size, binding and pa
- CBM and Chargeable Weight CalculatorTurn carton sizes into CBM, then compare actual and volumetric weight
- Carat Cost CalculatorEstimate diamond cost from carat weight, price per carat, shape, setti
Everyday
- 1 Hour Cycling Calories CalculatorOne hour on the bike spans 343 to 1,440 calories for a 180 pound rider
- 1 Hour Lunch Break CalculatorClock in at 8:30 and out at 5:00 with a 1 hour unpaid lunch: 7.5 paid
- 1 Million in Numbers1 million in numbers is 1,000,000, a 1 with six zeros. See the comma g
- 1 Weeks Ago From TodaySee the exact date 1 week ago from today, the weekday it fell on, the
- 1 in 60 Rule CalculatorWork the 1 in 60 rule: enter distance flown, distance to go, and how f
- 10 Day Payoff CalculatorEnter your balance, APR and payoff date to get per diem interest, the
Finance
- $100,000 Loan for 15 Years CalculatorSee the monthly payment on a $100,000 loan paid back over 15 years, co
- $15 an Hour Is How Much a Year?At $15 an hour, full time work pays $31,200 a year before tax and abou
- $15,000 Loan Over 5 Years CalculatorA $15,000 loan over 5 years costs $289.99 a month at 6%, with $2,399.4
- $20 an Hour Is How Much a Year?At $20 an hour, full time work pays $41,600 a year before tax. See the
- $25 an Hour Is How Much a Year?At $25 an hour, full time work pays $52,000 a year before tax. See the
- $30 an Hour Is How Much a Year?At $30 an hour, full time work pays $62,400 a year before tax. See the
Gaming
- Custom Dice RollerRoll any dice notation like 2d6+3 and see the odds: full range, averag
- D100 Dice RollerRoll 1 to 20 d100 dice with a modifier and target. Every face is exact
- D20 Dice RollerRoll a d20 online with advantage, disadvantage and modifiers. See the
- Donation Impact CalculatorSee what a stream donation delivers: the fee taken, the cash that land
- K/D CalculatorFree K/D calculator: divide kills by deaths in one step, add assists f
- Lottery Odds and Expected Value CalculatorSee the exact jackpot odds, the chance of any prize, and the expected
Health
- 10-Year ASCVD CalculatorCalculate your 10-year ASCVD risk using the ACC/AHA pooled cohort equa
- 10-Year ASCVD Risk CalculatorEstimate your 10-year risk of heart attack or stroke with the ACC/AHA
- 10-Year CV Risk CalculatorEnter your numbers and see how systolic blood pressure and diabetes mo
- 10-Year CVD Risk CalculatorEstimate 10-year cardiovascular risk from total cholesterol, HDL, bloo
- 10-Year CVD Risk CalculatorEstimate your 10-year risk of heart attack, stroke, heart failure or a
- 10-Year Cardiac Risk CalculatorSee how your cholesterol drives your 10-year heart risk, then find out
Home Improvement
- ADU Cost CalculatorCalculate accessory dwelling unit construction costs for detached suit
- Acreage CalculatorTurn length and width in feet, yards or meters into acres, square feet
- Aggregate Cost CalculatorEstimate the cost of gravel, crushed stone, or sand by converting proj
- Air Conditioner Room Size & BTU CalculatorCalculate the exact air conditioner BTU rating needed for your room si
- Aluminum Fence Cost CalculatorCalculate aluminum fence installation costs by linear feet, height, an
- Asphalt CalculatorTurn length, width and compacted thickness into tons of hot mix asphal
Kids School
- ACT Score CalculatorCalculate your ACT composite score, superscore, and STEM average. Conv
- ACT Score CalculatorTurn English, math and reading scores into an ACT composite. See the r
- Back to School Budget CalculatorBuild a per student back to school budget by grade, split the school l
- Back to School CountdownCount the days, weeks and weekdays until the first day of school, plus
- College Cost CalculatorAdd tuition, housing, books and fees, then grow each year to see the r
- College GPA CalculatorEnter each course, its credit hours and your letter grade to see your
Kitchen
- Air Fryer Conversion CalculatorConvert conventional oven recipes for an air fryer. Adjust baking temp
- Air Fryer Time and Temperature CalculatorConvert an oven recipe to your air fryer in one step. Drop the tempera
- Air Fryer to Oven ConverterAir fryer to oven converter: turn any air fryer temperature and time i
- Alcohol Dilution CalculatorWork out how much water to add to bring spirits down to a target stren
- BBQ Grill Size CalculatorWork out the grate area a cookout needs: 72 square inches per adult, 6
- BBQ Party CalculatorEnter adults, children and party hours to get the raw meat, sides, bun
Math
- 0.125 as a Fraction0.125 as a fraction is 125/1000, which cancels to 1/8. See the slot we
- 0.2 as a Fraction0.2 as a fraction is 2/10, which shrinks to 1/5. See the tenths column
- 0.25 as a Fraction0.25 as a fraction is 25/100, which cuts to 1/4. See the hundredths co
- 0.375 as a Fraction0.375 as a fraction is 375/1000, which strips to 3/8. See Euclid's div
- 1/10 as a Decimal1/10 is 0.1 as a decimal and 10 percent. See the long division, the pl
- 1/10 as a Percent1/10 as a percent is 10 percent. See the division step, a tenths conve
Pets
- Aquarium Glass Thickness CalculatorEstimate side and bottom glass thickness from water depth and tank len
- Aquarium Heater Size CalculatorFind the right aquarium heater wattage. Enter tank size, target and ro
- Aquarium Salt CalculatorWork out how much aquarium salt to add to a freshwater tank. Pick the
- Aquarium Tank Weight CalculatorAdd up the real weight of a fish tank: water at 8.34 lb a gallon, glas
- Aquarium Volume CalculatorConvert tank dimensions in inches to gallons, then subtract substrate,
- Aquarium Water Change CalculatorFind the right aquarium water change. Enter your nitrate reading and t
Tech
- Amp-Hour CalculatorTurn current in amps and run time in hours into battery capacity in am
- Amps to kVA CalculatorConvert amps and volts to kVA for single phase or three phase power. S
- Audio File Size Calculator: WAV, MP3 and Storage TimeCalculate audio file size for uncompressed WAV or compressed MP3 from
- Bandwidth CalculatorConvert Mbps to MB/s, add up what each person and device needs at once
- Battery Charge Time CalculatorEnter battery mAh, voltage and charger watts to see how long a full ch
- Battery Life CalculatorTurn mAh and current draw into real runtime, then see how much capacit
Text
- Case ConverterConvert text between UPPERCASE, lowercase, Title Case, Sentence case,
- Numbers to Words ConverterConvert numbers to words in one step: dollars and cents, plain words,
- Reading Level CalculatorPaste any text to get its Flesch-Kincaid grade, reading ease, Gunning
- Text to Speech Time CalculatorEstimate how long text to speech or narration takes: enter word count
- Word CounterCount words, characters, sentences and paragraphs as you type, with re
Travel
- Baggage Weight CalculatorCheck your checked bag against 11 US airline weight limits in pounds a
- Best Time to Fly CalculatorFind the cheapest day and time to fly. Enter your fare, planned day an
- Carry-On Size CalculatorCheck your bag against each airline's carry-on limit in inches and lin
- Check-In Time CalculatorCheck-in time calculator: enter your flight time and how you are getti
- Cross Exchange Rate CalculatorTurn two dollar quotes into a cross rate, then see what a spread on ea
- Currency ConverterConvert an amount with the real rate you get, then see what the bank s