Everyday Life CalculatorsAge, dates, work hours, sleep and household money: 30 free tools in one place
The quick calculations real life keeps throwing at you: how old you are to the day, how many days until a deadline, how many hours are on your time card, when to go to bed, and how to split the bill fairly. Each one is built, tested and maintained by a real person.
- Hand-checked formulas
- Runs in your browser, no data stored
- Free, no sign-up
- Mobile-first
Today at a glance: November 1, 2026 · 60 days left this year · updates live for your time zone
What are everyday life calculators?
Everyday life calculators are free online tools for the practical math of daily living: your exact age, the days between two dates, hours on a time card, the best bedtime for your wake-up time, and a fair tip or bill split. DexoCalc groups 30 of them into six categories. Each one follows official calendar, time and labor standards and is tested against known edge cases.
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Showing all 30 calculators
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Age & Birthday Calculators
Exact ages, age gaps and birthday milestones, calculated the way schools, clinics and government forms count them.
Age Calculator
Your exact age in years, months and days, plus totals in weeks, hours and seconds, from any date of birth.
Open calculatorChronological Age Calculator
Age in the years-months-days format used on school, speech-therapy and psychology test forms.
Open calculatorAge Difference Calculator
The exact age gap between two people, such as partners, siblings or parent and child.
Open calculatorBirthday Calculator
Find the weekday you were born on, count down to your next birthday and spot milestone birthdays.
Open calculatorHalf Birthday Calculator
Find the date exactly six months after your birthday, with Feb 29 and month-end birthdays handled correctly.
Open calculatorDays Alive Calculator
How many days, weeks and hours you have been alive, and the date you turn 10,000 days old.
Open calculatorDate & Countdown Calculators
Count days, add months, find weekdays and week numbers, with leap years and month-end edge cases handled correctly.
Date Calculator
Add or subtract days, weeks, months or years from any date to find deadlines and due dates.
Open calculatorDays Between Dates Calculator
Count the calendar days between two dates, with the option to include the end date.
Open calculatorDays Until Calculator
A live countdown to a trip, wedding, exam or holiday, shown in days, weeks and hours.
Open calculatorBusiness Days Calculator
Working days between two dates, skipping weekends and US federal holidays.
Open calculatorDay of the Week Calculator
Find the weekday for any past or future date, back to 1583.
Open calculatorWeek Number Calculator
Today's ISO-8601 week number, or the week number for any date you choose.
Open calculatorYears Calculator
How many full years lie between two dates, plus the leftover months and days.
Open calculatorMonth Calculator
Count the months between two dates, or add months to a date without month-end errors.
Open calculatorAnniversary Calculator
Time together in years, months and days, with upcoming milestone anniversaries and traditional gifts.
Open calculatorTime & Work Hours Calculators
Timesheets, shift hours, decimal payroll time and time-zone math for hourly workers, freelancers and managers.
Time Card Calculator
A weekly timesheet that handles lunch breaks, overtime, quarter-hour rounding and pay totals.
Open calculatorHours Calculator
Hours and minutes between two clock times, including overnight and split shifts.
Open calculatorTime Calculator
Add or subtract hours, minutes and seconds, or total several durations at once.
Open calculatorTime to Decimal Calculator
Convert hours and minutes to decimal hours for payroll, billing and invoices, or convert back.
Open calculatorTime Zone Converter
Compare local times across cities, with daylight saving applied, and find a meeting slot that works for everyone.
Open calculatorSleep & Daily Routine Calculators
Bedtimes, naps and sleep debt built on sleep-cycle science, and reviewed by a practising pharmacist.
Sleep Calculator
The best times to go to bed or wake up, based on 90-minute sleep cycles and the time you take to fall asleep.
Open calculatorNap Calculator
Time a 20-minute power nap or a 90-minute full-cycle nap so you wake up without grogginess.
Open calculatorSleep Debt Calculator
Add up the sleep you missed this week against your need, and get a realistic plan to catch up.
Open calculatorHousehold Money & Bills Calculators
Tips, shared bills, rent splits, power costs and family savings: the money math that comes up at home every week.
Tip Calculator
The tip and total for any bill at 15, 18, 20% or a custom rate, split per person.
Open calculatorSplit Bill Calculator
Split a bill evenly or by what each person ordered, with tax and tip shared fairly.
Open calculatorRent Split Calculator
Fair rent shares for roommates or couples, by room size, by income or as an equal split.
Open calculatorElectricity Cost Calculator
What one appliance, or your whole home, costs to run per day, month and year at your kWh rate.
Open calculatorMoving Cost Calculator
Compare a DIY truck move with professional movers for local and long-distance moves.
Open calculatorTrump Accounts Calculator
Project a child's Trump Account (IRC §530A) balance at age 18 from deposits and growth.
Open calculatorQuick Everyday Converters
Small conversions people look up all the time.
Roman Numeral Converter
Convert numbers, years and dates to Roman numerals and back, for tattoos, clocks and film credits.
Open calculatorWhich everyday calculator do I need?
Match your question to the right tool. Several of these are easy to mix up.
| If you want to know… | Use this calculator | Why this one |
|---|---|---|
| How old am I, or how old will I be on a set date? | Age Calculator | Gives years, months and days, plus totals in weeks, hours and seconds. |
| What age do I write on a school or psychology test form? | Chronological Age Calculator | Uses the borrowing method that standardized test manuals use. |
| How many days are there between two dates? | Days Between Dates | Lets you include or exclude the end date. |
| What date is 90 days from today? | Date Calculator | Adds or subtracts days, weeks, months or years from a date. |
| How many working days are left before a deadline? | Business Days Calculator | Skips weekends and US federal holidays. |
| How many hours did I work this week? | Time Card Calculator | Handles several days, lunch breaks, overtime and pay. |
| How long is it from 9:15 AM to 5:40 PM? | Hours Calculator | Works out one span between two clock times, including overnight. |
| What is 7 h 45 min as a decimal for payroll? | Time to Decimal | 7:45 becomes 7.75 hours, ready to multiply by your hourly rate. |
| When should I go to bed to wake up at 6 AM? | Sleep Calculator | Counts back in 90-minute cycles plus the time you take to fall asleep. |
How we build and check every everyday calculator
Behind each calculator is a real person, a documented method and a set of edge-case tests. A tool only goes live after it gives the right answer to every one of them.
Official standards first
Date tools follow the Gregorian calendar and ISO 8601. Time tools follow NIST time standards and real daylight-saving rules. Work-hour tools mirror US Department of Labor guidance on hours worked and rounding.
Formula shown on every page
Each calculator page shows its formula, a worked example and its assumptions in plain text, so you, a teacher or a payroll clerk can check the result by hand.
Expert review where it matters
Health-adjacent tools (sleep, nap and sleep debt) are reviewed by a pharmacist against CDC and American Academy of Sleep Medicine guidance. Money tools use published rates such as US EIA electricity prices.
Edge cases every date and time tool must pass
- Leap-day birthdays: Feb 29 ages in non-leap years
- Month-end math: Jan 31 + 1 month = Feb 28/29
- Century rule: 1900 is not a leap year, 2000 is
- Overnight shifts: 10 PM → 6 AM = 8 hours
- DST changeover: a 23-hour or 25-hour day
- ISO weeks: Dec 29–31 can belong to week 1 of the next year
Manzoor Ahmad
Calculator Developer · Pharmacist · Founder of DexoCalc
I’m a pharmacist who became a tech geek. I’ve spent more than 13 years in web development and SEO, and I design, code and test every calculator on DexoCalc myself. For the date, time and money tools here, my job is engineering accuracy: following the standards, writing the edge-case tests and showing the formulas openly. For the sleep tools, I also bring 9+ years of experience writing health and supplement content as a pharmacist. If you find a result that looks wrong, tell me. I fix confirmed errors quickly and note the change on the page.
- 13+ yrs web development
- Pharmacist, 9+ yrs health writing
- Owner, Drugs Bank Pharmacy
- Hand-tested formulas
Published · Last reviewed · Full author profile
Everyday calculators: frequently asked questions
Everyday life calculators are free online tools for the practical math of daily life: your exact age, the days between two dates, hours on a time card, the best bedtime, a fair tip or bill split, and what an appliance costs to run. DexoCalc's hub groups 30 of them into six categories so you can find the right one in a couple of clicks.
Yes, every calculator is free and needs no sign-up. All the calculations run in your own browser, so the dates, times, amounts and birthdays you type are not sent to or stored on our servers.
They follow the Gregorian calendar rules: a year divisible by 4 is a leap year, except century years, which must also be divisible by 400. Adding one month to January 31 gives the last day of February rather than spilling into March, and February 29 birthdays are handled explicitly. Every date tool is tested against these edge cases before it goes live.
By default it counts the days between the two dates, the same way most contracts and countdowns do, so 1 to 3 March is 2 days. Switch on the 'include end date' option when you need inclusive counting, for example for leave days or rental nights.
Enter clock-in and clock-out times plus any unpaid break, and the calculator subtracts the break from each shift. Optional rounding to the nearest 5, 6 or 15 minutes reflects the rounding practice the US Department of Labor describes in 29 CFR 785.48. Overtime is shown over 40 hours a week, the federal FLSA baseline; some states also have daily overtime rules.
Yes. The sleep, nap and sleep-debt calculators are built and reviewed by Manzoor Ahmad, a pharmacist with more than 9 years of experience in health and supplement writing. They use the commonly cited 90-minute sleep cycle together with the adult recommendation of 7 or more hours a night. They are educational tools, not a diagnosis. See a clinician if you have ongoing insomnia or daytime sleepiness.
Every calculator is designed, coded and tested by Manzoor Ahmad, a web developer with more than 13 years of experience and a practising pharmacist. Each tool's formulas are checked by hand against worked examples and official references (NIST time standards, ISO 8601, the US Department of Labor and the US EIA) before publication. Each page shows its own review date.
Yes. Every page is designed for mobile first. Use the Bookmark button to save this hub (Ctrl+D on Windows, Cmd+D on Mac, or Share > Add to Home Screen on a phone). You can also add DexoCalc as a preferred source on Google so our tools appear more often in your results.
Yes, please do. Tell us the everyday problem you want solved through the contact page. Requests that many people share are added to this hub first.
Standards & references we build on
- ISO 8601: Date and time format, International Organization for Standardization
- Time and Frequency Division, National Institute of Standards and Technology (NIST)
- Fact Sheet #22: Hours Worked Under the FLSA, US Department of Labor
- 29 CFR Part 785: Hours Worked (incl. §785.48 rounding), eCFR
- About Sleep, Centers for Disease Control and Prevention
- Recommended Amount of Sleep for a Healthy Adult, Journal of Clinical Sleep Medicine (AASM/SRS consensus)
- Electric Power Monthly, US Energy Information Administration
Missing a calculator you use every week?
Tell us the everyday problem and we’ll consider building it, and credit your idea on the page.
Suggest a calculator →DexoCalc calculators are for general information and planning. Payroll, legal deadlines and health decisions should be confirmed with your employer, a professional or a clinician. Calculations run locally in your browser, and we don’t store the values you enter.