All Tools

Convert Cups to Milliliters

Convert US cups to milliliters instantly. 1 cup = 236.588 ml. Includes metric cup difference, quick reference table, and plain-English formula.

Convert Tablespoons to Teaspoons

Convert tablespoons to teaspoons instantly. 1 tablespoon = 3 teaspoons. Includes quick reference table, practical recipe examples, and the reverse conversion.

Convert Ounces to Grams

Convert ounces to grams instantly. 1 oz = 28.3495 g (NIST exact). Includes a quick reference table, practical recipe examples, and the reverse grams-to-ounces conversion.

Convert Oven Temperature: °F to °C

Convert oven temperatures between Fahrenheit, Celsius, and Gas Mark. Instant results with a full quick-reference table for common baking temperatures.

Recipe Scaler

Scale any recipe up or down instantly. Enter original servings, desired servings, and an ingredient amount to get the scaled quantity. Works for cups, grams, or any unit.

Butter Converter

Convert butter between sticks, cups, grams, and tablespoons instantly. 1 stick = ½ cup = 8 tbsp = 113.4 g. USDA-sourced data.

Convert Pounds to Ounces

Convert pounds to ounces (and back) instantly. 1 lb = 16 oz exactly per NIST HB 44. Includes quick reference and cooking context.

US vs UK Cooking Measurements

Compare US and UK cooking measurements side-by-side: cups, tablespoons, pints, quarts, gallons in mL. Scale for any recipe quantity.

Baking Pan Size Converter

Calculate baking pan volume in cups and mL for round, square, and rectangular pans. Enter dimensions to compare pan sizes and find substitutes.

Egg Size Substitution Guide

USDA egg size chart with weights (Peewee to Jumbo) and substitution ratios relative to Large. Sourced from USDA AMS 7 CFR Part 56.

Yeast Converter

Convert yeast between active dry (tsp), instant (tsp), fresh (tsp), and packets. Manufacturer-sourced ratios from Fleischmann's.

Baby Clothing Size Chart

Find the right baby clothing size by age in months. US, EU, and UK size equivalents for newborn through 4T. Includes a full size chart.

Kids Shoe Size Chart

Find kids shoe sizes by foot length (inches or cm) and age. US, EU, and UK shoe size equivalents from infant to youth. Full size chart included.

Diaper Usage Estimator

Estimate how many diapers your baby needs per day and per month by age. Use for budgeting diaper purchases and stocking up before a newborn arrives.

Dog Age Calculator

Convert your dog's age to human years by size class (toy, small, medium, large, giant). Based on AAHA Canine Life Stage Guidelines. Not veterinary advice.

Cat Age Calculator

Convert your cat's age to human years using AAFP/AAHA Feline Life Stage Guidelines. Year 1 = 15 human years. Not veterinary advice.

Pet Weight Converter

Convert pet weight between pounds, kilograms, and ounces. Exact NIST factors. Useful for vet visits, diet tracking, and shipping.

Aquarium Volume Calculator

Calculate aquarium volume in US gallons and liters from tank dimensions. Supports rectangular and cylindrical tanks in inches or centimeters.

Aquarium Substrate Calculator

Calculate how many pounds or kilograms of gravel, sand, or planted substrate you need for any aquarium. Enter tank dimensions and desired depth.

Convert Kilograms, Pounds, and Stone

Convert kilograms, pounds, and stone instantly. 1 kg = 2.20462 lbs · 1 stone = 14 lbs = 6.350 kg. NIST-exact factors.

Running Pace Calculator

Calculate running pace, finish time, or distance. Works in min/mile and min/km. Find pace from time and distance, or project a race finish time.

BMI Calculator

Calculate body mass index (BMI) from weight and height in metric or imperial units. WHO classification table included. Not medical advice.

1-Rep Max Estimator

Estimate your 1-rep max (1RM) from a submaximal lift using Epley and Brzycki formulas. Includes a percentage table for training programming.

Plate Math Calculator

Find which plates to load on each side of the barbell. Supports lbs and kg, custom bar weight, and per-plate enabling. Shows closest achievable weight.

Body Fat Estimator

Estimate body fat percentage using the US Navy circumference method (Hodgdon & Beckett 1984). Requires height, waist, neck, and hip (women only). Not medical advice.

Square Footage Calculator

Calculate square footage from length and width in feet or inches. Instant results for rooms, flooring, tile, and paint projects.

Cubic Feet Calculator

Calculate cubic feet from length, width, and height. Use for storage units, moving boxes, mulch, gravel, and concrete volume estimates.

Paint Coverage Calculator

Calculate how much paint you need. Enter room dimensions and get gallons needed, with a high and low estimate based on industry-standard coverage (350–400 sq ft/gallon).

Convert Inches to Centimeters

Convert inches to centimeters instantly. 1 inch = 2.54 cm (exact, by international definition). Includes quick reference table and reverse cm-to-inches conversion.

Convert Feet to Meters

Convert feet to meters instantly. 1 foot = 0.3048 m (exact). Includes quick reference table, practical room measurement examples, and reverse meters-to-feet conversion.

Length Converter

Convert between meters, kilometers, feet, inches, yards, miles, centimeters, and millimeters. Live results, NIST-sourced factors.

Weight & Mass Converter

Convert between kilograms, pounds, ounces, grams, stone, and metric tonnes. Live results, NIST SP 811 conversion factors.

Volume Converter

Convert between liters, milliliters, US gallons, fluid ounces, cups, and cubic feet. Live results, NIST SP 811 exact factors.

Area Converter

Convert between square meters, square feet, acres, hectares, square kilometers, and more. Live results from NIST SP 811 exact factors.

Temperature Converter

Convert between Fahrenheit, Celsius, and Kelvin. Exact values, NIST SP 811 formulas. Includes absolute zero reference.

Speed Converter

Convert between mph, km/h, knots, m/s, and ft/s. Live results using NIST SP 811 and BIPM nautical mile definition.

Time Zone Converter

Convert time between any two IANA time zones instantly. Works in your browser — no sign-up needed.

Date Difference Calculator

Calculate the exact number of days, weeks, and months between any two dates. Works instantly in your browser.

Age Calculator

Calculate your exact age in years, months, and days from any birth date. Works in your browser with no sign-up.

Business Days Calculator

Add or subtract business days from any date. Counts Monday–Friday only. Fast, browser-based, no sign-up.

Decimal Hours Converter

Convert decimal hours to hours and minutes or vice versa. Instantly convert 7.5 hours to 7h 30m and back.

Unix Timestamp Converter

Convert Unix timestamps to readable dates or any date to a Unix epoch timestamp. Works in your browser instantly.

Currency Converter

Convert between 40+ currencies using live exchange rates updated hourly. Indicative rates — not for financial transactions.

Miles to Kilometers

Convert miles to kilometers or km to miles for driving distances. 1 mile = 1.609344 km (NIST exact definition).

Fuel Economy Converter

Convert between mpg (US), L/100km, and km/L instantly. Uses NIST-defined exact factors for US gallons and miles.

Fuel Volume Converter

Convert US gallons, Imperial gallons, and liters for fuel. Uses NIST-defined exact conversion factors.

Shoe Size Converter

Convert shoe sizes between US, UK, EU, and Japanese sizing for men and women. Based on ISO 19407:2015.

Clothing Size Converter

Convert clothing sizes between US, UK, EU, and Japanese sizing for men and women. Based on ISO 8559-1:2017.

Luggage Size Calculator

Calculate your bag's linear inches (L+W+H) in inches and cm. Check airline carry-on and checked baggage limits.

Yarn Weight Chart

Convert yarn weight categories (lace to jumbo) to ply count, WPI, and needle/hook size. Based on Craft Yarn Council CYC standards.

Knitting Needle Size Chart

Convert knitting needle sizes between US numbers, metric mm, and old UK/Canadian sizes. Covers all standard sizes from 2.0 mm to 25 mm.

Crochet Hook Size Chart

Convert crochet hook sizes between US letter labels, metric mm, and old UK/Canadian sizes. From B-1 (2.25 mm) to P/Q (15 mm).

Fabric Yardage Calculator

Calculate how many yards (or meters) of fabric you need. Enter piece dimensions, seam allowance, number of pieces, and fabric width.

Bead Size Chart

Convert seed bead aught sizes (15/0 to 6/0) to mm diameter. Includes beads-per-gram estimates for budgeting projects.

Drill Bit Size Chart

Look up drill bit sizes across all four systems: fractional inches, metric mm, wire gauge numbers, and letter sizes. From 0.35 mm to 25 mm.

Sandpaper Grit Equivalents

Compare sandpaper grit numbers across CAMI (US), FEPA (EU P-grades), and JIS (Japanese) standards. From grit 40 to 3000.

Tire Size Calculator

Calculate tire sidewall height, overall diameter, and circumference from a P225/65R17-style code. Results in mm and inches.

Torque Converter

Convert torque between Newton-meters (Nm), foot-pounds (ft-lb), inch-pounds (in-lb), and kilogram-force meters (kgf·m). NIST-sourced factors.

Horsepower Converter

Convert between mechanical horsepower (hp), kilowatts (kW), and metric horsepower (PS/CV). NIST-sourced conversion factors.

0–60 mph ↔ 0–100 km/h Converter

Estimate 0–100 km/h acceleration time from a 0–60 mph figure using constant-acceleration math. Explains why the two tests differ.

Tire Pressure Converter

Convert tire pressure between PSI, bar, and kilopascals (kPa). NIST-sourced factors. Includes typical passenger car pressure ranges.

Ring Size Converter

Convert ring sizes between US, UK letter, EU (ISO circumference in mm), and Japanese sizing. Includes inner diameter and circumference in mm.

Hat Size Converter

Convert hat sizes between US fractions, EU centimeters, UK, and S/M/L/XL labels. Measure your head circumference to find your size.

Bra Size Converter

Convert bra sizes between UK, US, EU, French, and Australian sizing. Separate band and cup conversion tables. Cup letters differ above DD.

Glove Size Chart

Find your glove size from hand circumference in cm. Converts between S/M/L/XL labels and US/EU numeric sizes for work and fashion gloves.

Data Storage Converter

Convert bytes, KB, MB, GB, and TB between SI (÷1000) and binary (÷1024) systems. Understand why 1 GB ≠ 1 GiB.

Bandwidth Converter

Convert internet speeds between Mbps, MB/s, Gbps, KB/s, and GB/s. Understand the difference between bits per second and bytes per second.

Pixel Unit Converter

Convert CSS units: pixels (px) to rem, em, and points (pt). Set any base font size to match your design system.

Aspect Ratio Calculator

Simplify an aspect ratio from width and height, or find a missing dimension given a known ratio. Supports any custom ratio plus common presets.

DPI / PPI Calculator

Calculate DPI or PPI from pixel dimensions and print size. Includes quality guidance: what DPI is good enough for professional print vs screen display.

Color Converter

Convert colors between HEX, RGB, and HSL formats. Edit any field and see all three update instantly with a live color swatch.

File Size Estimator

Estimate video file size from duration and bitrate. Calculate how much storage a recording will need before you capture it.

Words to Pages Calculator

Convert word count to pages (or pages to words) with configurable font size, line spacing, and margins. Supports standard academic and manuscript formats.

Reading Time Calculator

Estimate reading time from word count using a configurable WPM (default 238 wpm — the median from Brysbaert's 2019 meta-analysis of 190 studies).

Paper Size Reference

Reference table for standard paper sizes: A3, A4, A5, Letter, Legal, Tabloid, and Executive in mm, inches, and PostScript points.

Rainfall Converter

Convert rainfall between millimeters and inches instantly. 1 inch = 25.4 mm exactly (NIST SP 811). Useful for comparing weather data and irrigation specs.

Seed Spacing Calculator

Calculate how many plants fit in your garden rows. Enter row length, plant spacing, and number of rows to get total plant count.

Lawn Seed Calculator

Calculate how many pounds of grass seed you need. Enter lawn area and your seed's application rate. Supports new seeding and overseeding rates.

Mulch Volume Calculator

Calculate how much mulch, topsoil, or compost you need in cubic yards and bags. Enter area and depth — works for any loose landscaping material.

USDA Plant Hardiness Zone Finder

Find your USDA Plant Hardiness Zone by ZIP code. Shows zone code and minimum temperature range (°F and °C). Data from USDA 2023 PHZM.

Compound Interest Calculator

Calculate compound interest with optional monthly contributions. See final balance, total interest earned, and a year-by-year breakdown chart.

Loan Amortization Calculator

Calculate your monthly loan payment and see a full amortization schedule. Enter an extra payment to see how much interest and time you save.

Mortgage Payment Calculator

Estimate your monthly mortgage payment including principal, interest, property tax, insurance, HOA, and PMI. Shows the math behind each component.

APR vs APY Calculator

Convert APR to APY or APY to APR for any compounding frequency. Understand the difference between stated and effective interest rates.