Calculators Tools

Solve proportions and cross-multiplication problems. Find the missing value in a/b = c/d with step-by-step solutions.

Calculate circle area, circumference, radius, and diameter from any one known value. Also computes arc length, sector area, and chord length for a given central angle.

Calculate DPI (dots per inch), image dimensions, and print sizes. Convert between pixels and physical dimensions for printing and displays.

Calculate and simplify ratios to lowest terms. Find GCD, decimal ratios, percentages, and generate equivalent ratios instantly.

Count down to special events and important dates. Perfect for weddings, birthdays, vacations, project deadlines, and celebrations with live time tracking.

Check if any year is a leap year. Understand leap year rules and find past or future leap years instantly.

Calculate the square root of any number. Instantly shows the result, perfect square check, simplified radical form, and cube root.

Calculate aspect ratios, find missing dimensions, and convert between different aspect ratios for videos, images, and screens. Supports 16:9, 4:3, 21:9, and more.

Calculate probabilities for events — shows fraction, decimal, percentage, complement, and odds. Supports single events and two independent events (AND/OR).

Calculate the duration between two dates and times. Get results in days, hours, minutes, and seconds.

Calculate rectangle area, perimeter, and diagonal length from length and width. Instantly see aspect ratio with a visual diagram.

Calculate triangle area, perimeter, all angles and sides from any valid combination of known values. Supports SSS, SAS, ASA, and AAS input modes.

Add or subtract days, weeks, months, or years from any date to calculate future or past dates with precision.

Calculate the exact number of days between two dates. Get instant results for total days, business days, weekends, and more. Perfect for project planning, vacation tracking, and deadline management.

Set a countdown timer for any duration. Perfect for cooking, workouts, meetings, and time management with customizable timers and preset options.

Calculate central tendency measures — mean, median, mode, and range — for any set of numbers, with frequency distribution.

Find out what day of the week any date falls on - past, present, or future dates instantly.

Calculate powers and exponents with support for negative and fractional exponents. Shows step-by-step working, reciprocal form, and root equivalents.

Calculate the precise difference between two dates in years, months, weeks, days, hours, minutes, and seconds. Perfect for tracking project durations, age calculations, event countdowns, and more.

Calculate words per page for different formats. Convert between word count and page count based on font size, line spacing, and page size.

Calculate any side of a right triangle using the Pythagorean theorem (a² + b² = c²). Find the hypotenuse or either leg instantly with formula visualization and triangle diagram.

Calculate business days between two dates, excluding weekends and optional holidays for accurate work-day planning.

Predict child adult height based on parent heights using the Mid-Parental Height method. Calculate how tall your child will be with genetic predictions.

Calculate recommended study hours for exams based on material volume, difficulty level, and available time. Get a personalized daily study schedule.

Calculate days until any future date with countdown for important events, deadlines, and milestones.

Calculate ISO week number for any date. Find which week (1-53) of the year any date falls in.

Calculate PPI (pixels per inch) for screens and displays. Find pixel density from resolution and screen size for phones, tablets, monitors, and TVs.

Boost productivity with the Pomodoro Technique: work in focused 25-minute intervals with short breaks. Perfect for studying, coding, writing, and focused work.

Add or subtract hours, minutes, and seconds to/from any time. Perfect for calculating flight arrivals, work schedules, cooking times, and time zone conversions.

Calculate baby growth percentiles for weight, length/height, and head circumference based on WHO and CDC growth standards. Track your baby development from 0-36 months.

Calculate which day number (1-365/366) any date is in its year. Track progress through the year and find milestone days.

Online stopwatch timer with lap tracking. Measure time intervals precisely for sports, cooking, work tasks, and more.

Display current time in multiple cities around the world. Compare time zones and schedule across regions.

Full-featured scientific calculator with trigonometric, logarithmic, exponential functions, memory operations, and calculation history

Calculate percentage of any number, find what percent one number is of another, percentage increase/decrease, and percentage difference with real-time results

Calculate grade point average from grades. Support multiple GPA scales (4.0, 5.0, 10.0), letter grade to GPA conversion, weighted/unweighted GPA, semester GPA and cumulative GPA tracking

Calculate final grade based on assignments and weights. Support multiple assignment categories (homework, quizzes, tests, final exam) with custom weights, show current grade and what's needed on remaining assignments

Calculate with fractions - add subtract multiply divide. Support all operations with automatic simplification to lowest terms, mixed number support, decimal conversion, and step-by-step solution display

Calculate standard deviation and variance. Support both population and sample statistics, paste data from Excel/CSV, show mean, median, variance, standard deviation, and complete statistical analysis

Calculate cumulative college GPA across multiple semesters. Track overall GPA, major GPA, and institutional GPA separately. Supports transfer credits, honors eligibility checking, and semester-by-semester breakdown

Calculate what score you need on your final exam to achieve your target grade. Enter your current grade, final exam weight, and desired grade to instantly see the required final exam score with achievability status

Solve quadratic equations ax²+bx+c=0 instantly. Get real and complex roots, discriminant, vertex, graph visualization, and step-by-step solutions. Perfect for students, teachers, and professionals.

Calculate your test score percentage and letter grade from points earned. Instantly see your grade, points missed, and how many more points you needed for the next grade up.

Calculate tip amounts and split bills easily. Enter bill amount, tip percentage, and number of people to see tip amount, total cost, and per-person amounts. Includes preset tip percentages (15%, 18%, 20%, 25%).

Calculate MPG and fuel efficiency. Support both US (miles/gallons) and metric (km/liters) units. Shows fuel efficiency rating, cost per mile/km, and annual fuel cost estimates.

Calculate monthly mortgage payment with principal, interest, property taxes, insurance (PITI), and HOA fees. Shows amortization schedule, total interest paid, and payoff date with extra payment scenarios.

Compare the true cost of renting vs buying a home over time. Calculate breakeven point, equity buildup, investment opportunity cost, and get a personalized recommendation based on your specific situation.

Calculate auto loan payments and interest with trade-in value, down payment, sales tax, registration fees, and other costs. Compare financing options and see total cost of vehicle ownership.

Convert hourly wage to annual salary with overtime calculations. Calculate monthly, biweekly, weekly, and daily pay equivalents for full-time and part-time schedules.

Calculate how much you need to save for retirement. Project savings growth, estimate monthly retirement income, and see if you're on track to meet your goals with Social Security and inflation adjustments.

Calculate how your money grows with compound interest. Enter principal, interest rate, time period, and compounding frequency to see final amount, total interest earned, and year-by-year growth breakdown.

Calculate how your savings grow over time with regular deposits. See final balance, total contributions, and interest earned. Includes goal-based mode to find out how much you need to save monthly to reach your target.

Calculate inflation-adjusted values using historical CPI data from 1950-2026. See what past dollars are worth today, or project how much you'll need in the future to maintain purchasing power.

Calculate debt payoff timeline with different strategies. Compare snowball (smallest balance first) vs avalanche (highest interest first) methods to find the fastest and cheapest way to become debt-free.

Calculate monthly car lease payments from MSRP, negotiated price, residual value, and money factor. See depreciation fee, finance fee, effective APR, and total lease cost.

Calculate simple interest using the I = P × r × t formula. Enter principal, annual rate, and time period to see interest earned, total amount, daily/monthly/yearly accrual, and a comparison with compound interest.

Calculate your total net worth by entering assets and liabilities by category. See asset allocation, liability breakdown, debt-to-asset ratio, and your financial health snapshot.