All free online tools and calculators

Measure elapsed time and record individual lap results.

Alternate work, rest, and repeat rounds.

Set a labeled one-time alarm in your browser.

Display the current time in a large 12- or 24-hour format.

Run a live days, hours, minutes, and seconds countdown to or from an event.

Keep a steady, adjustable musical tempo.

Calculate the calendar time between two dates in years, months, weeks, and days.

Find exact elapsed days, hours, minutes, and seconds between two date-times.

Calculate the time between two clock times, including periods that cross midnight.

Find the weekday for any valid calendar date.

Move a date-time forward or backward by years, months, weeks, days, hours, minutes, or seconds.

Count working days between dates with inclusive options, custom weekends, and holidays.

Calculate age on today’s date or another selected date with calendar-accurate years, months, and days.

Convert a date and time between IANA time zones with daylight-saving changes applied.

Convert seconds, minutes, hours, days, weeks, months, and years using clearly stated assumptions.

Convert decimal hours to hours and minutes or convert clock-style hours and minutes to decimal time.

Find a date’s ISO week number, ISO week-year, week start, and week end.

Convert Unix seconds or milliseconds to readable date-time values and convert date-times back to Unix time.

See remaining time at a glance with a clear visual dial.

Use calm motion to show time without stressful digits.

Display an exam title, instructions, and countdown.

Use green, warning, and overtime zones while presenting.

Build balanced random groups from a list of people.

Shuffle people into numbered seating positions.

Visualize surrounding volume using your device microphone.

Signal go, wrap-up, or stop with a large color display.

Track scores for two teams with clear controls.

Track several independent counts at the same time.

Calculate adult body mass index from height and weight.

Estimate adult daily energy use and inspect an optional arithmetic scenario using visible assumptions.

Estimate adult basal metabolic rate using the Mifflin-St Jeor equation.

Estimate adult body-fat percentage from body measurements using the U.S. Navy method.

Compare four historical adult reference-weight formulas based on height without treating them as a health target.

Pick names or items fairly without repeats.

Generate a random whole number within a custom range.

Spin a reusable wheel of names or choices.

Roll one to twenty fair virtual dice with selectable sides and a modifier.

Make a quick random heads-or-tails choice.

Reveal a playful random answer to a simple question.

Run a randomized four-lane race.

Alternate focused work sessions and reset breaks.

Plan and run a timed multi-step routine.

Follow calm visual cues for paced breathing.

Find a percentage of a number, one number as a percentage of another, or the whole from a known percentage.

Convert common length, weight, and volume units, including pints, quarts, ounces, and inches.

Add, subtract, multiply, and divide fractions.

Calculate mean, median, mode, and range.

Find the amount and percentage of an increase or decrease.

Calculate increase and percentage growth between two values.

Calculate decrease and percentage reduction between two values.

Simplify a ratio and scale it to another quantity.

Evaluate common powers, roots, logarithms, and trigonometric functions.

Calculate sample or population standard deviation and variance.

Calculate area for common two-dimensional shapes.

Calculate volume for common three-dimensional shapes.

Convert between Fahrenheit, Celsius, and Kelvin.

Calculate pace, speed, distance, or finish time.

Estimate monthly payments and total interest.

Estimate payoff time and total interest cost.

Project compound growth with optional recurring contributions.

Estimate an affordable home price from income, debts, rate, and down payment.

Estimate principal and interest for a fixed-rate mortgage.

Compare estimated monthly renting and homeownership costs.

Estimate a savings target from essential monthly expenses.

Calculate the share of gross monthly income used for debt payments.

Compare total assets and liabilities to calculate net worth.

Estimate the monthly amount needed to reach a savings target.

Calculate gain or loss, total return, and money-weighted annualized return.

Project future retirement savings from current balance and contributions.

Compare monthly income, expenses, and money remaining.

Calculate a tip and split the total fairly.

Compare package prices to find the better value.

Calculate margin, selling price, cost, and gross profit.

Calculate selling price, profit, markup, and the resulting margin.

Calculate sale price, savings, stacked discounts, or an original price.

Add sales tax to a price or find the pre-tax price and tax within a total.

Calculate margin, selling price, cost, and gross profit.

Calculate selling price, profit, markup, and the resulting margin.

Find the sales volume and revenue needed to cover fixed and variable costs.

Measure return on ad spend, profit, and customer acquisition cost.

Calculate total production cost and cost for each unit.

Estimate the hourly rate needed to cover income, overhead, taxes, and billable time.

Calculate marketing and sales cost for each new customer.

Project monthly and annual recurring subscription revenue.

Compare cash received and cash paid to estimate net cash flow.

Measure how often inventory is sold and replaced.

Measure advertising revenue returned for every dollar spent.

Convert hourly pay into daily, weekly, monthly, and annual gross pay.

Convert an annual salary into monthly, weekly, daily, and hourly gross pay.

Estimate take-home pay from gross pay using withholding percentages, fixed deductions, and pay frequency that you enter.

Estimate regular, overtime, and total gross pay for a workweek.

Calculate new annual gross salary from a percentage raise, a fixed annual raise, or both.

Calculate commission and total pay from sales performance.

Estimate additional and total gross pay from an hourly shift premium.

Estimate paid-time-off earned, used, and remaining over a selected period.

Estimate a freelance hourly rate from a pre-tax owner-pay target, business expenses, contingency, collection risk, and billable time.

Compare two job offers using pay, bonus, benefits, commute, and paid time off.

Estimate an equivalent salary using user-entered cost-of-living indexes.

Estimate gross severance from salary, service, policy weeks, and additional compensation.

Estimate wall area and gallons of paint needed for a room.

Estimate flooring area, waste allowance, and package quantity.

Calculate rectangular area and total multiple spaces.

Estimate tile count from room and tile dimensions with waste.

Estimate cubic yards of concrete for a slab.

Estimate cubic yards of mulch from bed area and depth.

Estimate gravel volume, weight, and purchasable quantity.

Calculate lumber volume in board feet from board dimensions and quantity.

Estimate topsoil volume from area and depth.

Add a base quote, labor, fuel, packing, storage, tolls, and other entered moving costs.

Estimate electricity use and operating cost for an appliance.

Estimate roof area, waste, and shingle squares.

Estimate fence panels, posts, and project length.

Estimate deck area and board quantity.

Estimate wallpaper rolls from room dimensions and roll coverage.

Estimate a basic cooling capacity range from room area.

Count words, characters, sentences, and paragraphs.

Convert text to upper, lower, title, or sentence case.

Remove repeated lines while preserving the first occurrence.

Sort lines alphabetically, numerically, or in reverse.

Identify the most frequently used words in text.

Normalize spaces, blank lines, and common formatting problems.

Compare two blocks of text and summarize line differences.

Estimate reading level from words, sentences, and syllables.

Calculate a score percentage and letter grade.

Combine category scores using custom weights.

Find the final-exam score needed to reach a target course grade.

Calculate semester and cumulative GPA using courses, credits, and a customizable grade scale.

Convert correct answers, missed answers, or earned points into a percentage and letter grade.

Estimate reading and speaking time from word count.

Enter classroom content once and create quizzes, answer keys, worksheets, flash cards, word searches, matching exercises, and study guides.

Create a printable short-answer worksheet from prompts.

Create printable study cards from terms and definitions.

Generate a printable word-search puzzle from a word list.

Choose students fairly without repeats.

Run a large classroom countdown with an activity label.

Create a clear scoring rubric with criteria and performance levels.

Format basic website, book, and article citations.

Organize topics, key points, and questions into a printable study guide.

Build a focused, classroom-ready lesson from objectives through closure and assessment.

Turn a topic into clear, measurable learning objectives teachers can review and revise.

Map lesson activities and evidence of learning to teacher-selected standards.

Plan supports, access points, and extensions for a classroom activity.

Create a concise schedule, procedure guide, and lesson plan for a substitute teacher.

Create quick printable checks for understanding at the end of a lesson.

Turn teacher-entered grade, purpose, topic, format, and requirements into an editable writing assignment.

Arrange teacher-entered terms into an editable organizer with blank definition, example, and contrast fields.

Track local IDs, standards, assessments, dates, scores, and notes on this device with progress summaries and exports.

Summarize anonymous scores with an average, highest, lowest, and count above or below an 80% threshold.

Review teacher-entered attendance patterns locally without server storage.

Draft clear family messages while keeping entered details exclusively on the teacher's device.

Draft constructive, editable progress comments locally for teacher review.

Create a clear classroom newsletter for printing or local PDF export.

Prepare and retain conference notes exclusively on the teacher's device.

Create and rotate practical classroom responsibilities.

Track classroom supply quantities locally on the teacher's device.

Scale every ingredient for a different number of servings or batch size.

Convert common kitchen volumes into cups, tablespoons, teaspoons, and milliliters.

Convert oven temperatures between Fahrenheit, Celsius, and gas-mark estimates.

Calculate ingredient percentages from total flour weight.

Calculate hydration, total dough weight, and ingredient percentages.

Scale batter by comparing round or rectangular pan areas.

Add ingredient, packaging, labor, and overhead costs for a recipe batch.

Calculate cost per serving, menu price, and food-cost percentage.

Estimate total food quantity from guests and portion size.

Add preparation, cooking, resting, and buffer time to plan when to start.

Find practical replacements for common cooking and baking ingredients.

Track food quantities and review dates so ingredients get used instead of forgotten.

Turn entered weekly meals into a printable ingredient checklist with exact duplicate entries removed.

Look up minimum internal cooking temperatures for common foods.

Run several independently labeled cooking timers on one screen.