524+ Free Calculators & Tools
Instant, accurate calculations for work, finance, energy, health, math, and productivity. No signup required.
Finance (129 tools)
401k Calculator
Estimate your 401k balance at retirement based on contributions, employer match, and investment growth.
401(k) Match Calculator
Calculate your employer 401(k) match and how much free money you are leaving on the table.
Accounts Receivable Days Calculator
Calculate days sales outstanding (DSO) to see how quickly customers pay their invoices.
Adjustable Rate Mortgage Calculator
Estimate payments for an ARM with initial fixed rate and future adjustment periods.
Affiliate Commission Calculator
Estimate affiliate earnings based on product price, commission rate, and expected sales.
Amazon FBA Calculator
Estimate Amazon FBA fees, costs, and profit for a product.
Amortization Calculator
Generate a full loan amortization schedule showing principal and interest over time.
Annuity Calculator
Calculate the future value or payout of an annuity investment.
APR Calculator
Calculate the annual percentage rate including fees for loans and credit.
APY Calculator
Calculate annual percentage yield including compound interest to compare savings accounts and CDs.
ARR Calculator
Calculate Annual Recurring Revenue (ARR) from monthly recurring revenue or subscription pricing.
Auto Lease Calculator
Estimate monthly lease payments and total lease cost for a vehicle.
Work Tools (111 tools)
ACT Score Calculator
Estimate your ACT composite score from section scores.
Aspect Ratio Calculator
Calculate the aspect ratio from width and height, or find new dimensions maintaining a ratio.
Bandwidth Calculator
Estimate required bandwidth for video calls, streaming, and multiple users.
Bike Commute Calculator
Estimate commute time, calories burned, and CO2 saved by biking instead of driving.
Bonus Calculator
Estimate your take-home bonus pay after federal withholding, Social Security, Medicare, and state taxes.
Book Reading Time Calculator
Estimate how long it will take to read a book based on page count and reading speed.
Carpool Savings Calculator
Estimate how much money you can save by carpooling to work or school.
Commission Calculator
Calculate sales commission based on sale amount and commission rate.
Commute Cost Calculator
Estimate the monthly and annual cost of commuting by car or transit.
Contractor Rate Calculator
Calculate a contractor hourly or project rate based on employee salary equivalent, overhead, and profit margin.
Countdown Timer
Set a simple countdown timer in hours, minutes, and seconds.
Data Transfer Calculator
Estimate time to transfer data between locations based on bandwidth.
Math (87 tools)
Absolute Value Calculator
Find the absolute value of any real number.
Age Calculator
Calculate exact age in years, months, and days from birth date.
Average Calculator
Calculate mean, median, and sum from a list of numbers.
Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal.
Binomial Probability Calculator
Calculate the probability of exactly k successes in n independent trials.
Break Even Calculator
Find the number of units you need to sell to cover fixed and variable costs.
Chi-Square Calculator
Calculate chi-square statistic and p-value for contingency tables.
Circle Calculator
Calculate area, circumference, diameter, and radius of a circle.
Combination Calculator
Calculate combinations nCr for counting and statistics.
Combination with Repetition Calculator
Calculate combinations where items can be chosen more than once.
Complex Number Calculator
Add, subtract, multiply, or divide two complex numbers.
Confidence Interval Calculator
Calculate confidence intervals for sample means and proportions.
Health & Fitness (76 tools)
A1C Calculator
Convert average blood glucose to A1C percentage and vice versa.
Alcohol Calorie Calculator
Estimate calories from beer, wine, spirits, and cocktails.
Baby Growth Percentile Calculator
Estimate baby weight and length percentile based on WHO growth data.
BAC Calculator
Estimate blood alcohol content based on drinks, body weight, gender, and time elapsed.
BAI Calculator
Calculate your Body Adiposity Index (BAI) using hip circumference and height.
Bench Press Calculator
Estimate your bench press one-rep max based on reps and weight.
Blood Pressure Calculator
Check your blood pressure category based on systolic and diastolic readings.
BMI Calculator
Calculate your Body Mass Index and see your weight category.
BMR Calculator
Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation.
Body Fat Calculator
Estimate body fat percentage using the U.S. Navy method.
Body Frame Calculator
Determine your body frame size from wrist circumference and height.
Body Surface Area Calculator
Calculate body surface area using the Mosteller formula for medication dosing and clinical use.
Energy (27 tools)
Appliance Energy Calculator
Calculate the energy cost of running appliances.
Battery Capacity Calculator
Calculate battery runtime and Watt-hours.
Battery Charge Time Calculator
Estimate how long it takes to charge a battery from capacity and charge current.
Battery Life Calculator
Estimate battery runtime based on capacity and device power draw.
Carbon Footprint Calculator
Estimate your annual carbon footprint from electricity usage.
Carbon Offset Calculator
Estimate carbon offset cost for flights, driving, and home energy use.
Electricity Cost Calculator
Estimate your monthly electricity bill based on usage and rate.
Energy Consumption Calculator
Estimate daily, monthly, and annual energy use of appliances and electronics.
EV Charging Cost Calculator
Calculate the cost to charge your electric vehicle at home or public stations.
EV Charging Time Calculator
Estimate how long it takes to charge an electric vehicle based on battery size and charger power.
EV Range Calculator
Estimate electric vehicle range based on battery capacity and efficiency.
Fuel Efficiency Calculator
Convert between MPG, L/100km, and km/L to compare vehicle fuel efficiency.
AI Productivity (31 tools)
AI API Cost Estimator
Estimate LLM API costs from input and output tokens, requests, and model pricing.
AI Image Cost Calculator
Estimate the cost of generating images with AI services like Midjourney, DALL-E, or Stable Diffusion APIs.
AI Search Cost Calculator
Estimate the monthly cost of AI-powered search and retrieval APIs by query volume.
AI Translation Cost Calculator
Estimate translation API costs based on character or word volume.
AI Video Cost Calculator
Estimate the cost of generating AI videos based on duration, resolution, and model pricing.
AI Voice Cost Calculator
Estimate text-to-speech and AI voice generation costs from character count and model pricing.
Async Video Cost
Estimate the monthly cost of async video messaging platforms by user count, videos sent, and storage.
Bio Generator
Generate a professional or personal bio for LinkedIn, Twitter, portfolios, and more.
Blog Title Generator
Generate catchy blog post titles.
ChatGPT Cost Calculator
Estimate API cost for OpenAI GPT models based on input and output tokens.
Cold Email Generator
Generate a simple cold email template for outreach.
Content Calendar Generator
Plan a content calendar by calculating total posts, production hours, and publishing dates from frequency and timeframe.
Generators (43 tools)
Anagram Solver
Find possible anagrams and rearrangements of letters from any word or phrase.
Barcode Generator
Generate a free barcode image from any text or number.
Blog Outline Generator
Generate a structured blog post outline from a topic.
Case Converter
Convert text between uppercase, lowercase, title case, and sentence case.
Character Counter
Count characters, words, and estimate reading time for tweets, posts, and essays.
Coin Flip
Flip a virtual coin.
Color Palette Generator
Generate random color palettes.
Dice Roller
Roll virtual dice with any number of sides.
Email Signature Generator
Generate a simple HTML email signature from your contact details.
Flesch Reading Ease Calculator
Calculate Flesch Reading Ease score to measure how readable your text is.
Hashtag Generator
Generate hashtag suggestions from a keyword or topic.
Invoice Generator
Generate a simple invoice total from line items, tax, and discounts.
Unit Converters (20 tools)
Area Converter
Convert between square meters, square feet, acres, and hectares.
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to text.
CSV to JSON Converter
Convert CSV data into a JSON array of objects.
Currency Converter
Convert between major currencies using approximate exchange rates.
Data Storage Converter
Convert between Bytes, KB, MB, GB, and TB.
HTML Entity Encoder / Decoder
Encode special characters to HTML entities or decode entities back to readable text.
HTML to Markdown Converter
Convert simple HTML tags into Markdown formatting.
JSON Formatter
Validate and pretty-print JSON data.
JSON to CSV Converter
Convert a simple JSON array of objects into CSV format.
Length Converter
Convert between meters, feet, inches, centimeters, kilometers, and miles.
Markdown to HTML Converter
Convert basic Markdown formatting into HTML.
Power Converter
Convert between Watts, kilowatts, horsepower, and BTU/hr.