Conversions & Units
Free Conversions & Units calculators with instant results, clear explanations and worked examples — no sign-up, available in 9 languages.
Convert between units of length, weight, volume, temperature, speed, area and data, plus everyday kitchen and metric–imperial swaps. These are the go-to tools when a recipe, a manual or a label uses units you do not work in and you need the exact equivalent in seconds.
All Conversions & Units calculators
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Aspect Ratio Calculator
Calculate missing width or height from a target aspect ratio, or simplify pixels to lowest-term ratio (16:9, 4:3, 21:9). Instant rectangle preview.
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Download Time Calculator
Calculate download time accurately. Handles decimal (MB=10⁶) vs binary (MiB=2²⁰) prefixes and bits-vs-bytes for far more accurate results. Free.
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Fuel Economy Converter
Fuel economy converter: switch between mpg (US & UK), L/100km, km/L, and mi/L instantly, with a visual bar showing the inverse mpg-vs-litres relationship.
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IP Subnet Calculator
Calculate network, broadcast, host range, mask, wildcard and usable hosts for any IPv4 or IPv6 CIDR. Split blocks into subnets and plan VLSM. Free, instant.
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Land Area Converter
Land area converter: m², km², hectares, acres, sq ft, sq yd, and South-Asian units — bigha, kanal, marla, katha, cent. Includes a to-scale plot visualiser.
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Number Base Converter
Convert any number between binary, octal, decimal, hex and any base 2–36 — with a step-by-step positional breakdown showing digit × base^place.
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PPI & DPI Calculator
PPI and print size calculator. Find screen pixel density, print dimensions from pixels, or pixels needed for a target print size. Understand PPI vs DPI.
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Ring Size Converter
Ring size converter between EU/ISO, US, UK and Japanese systems. Enter circumference, diameter or a known size for all four plus a to-scale diagram.
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Roman Numeral Converter
Convert between Arabic numbers and Roman numerals instantly. See the step-by-step additive breakdown (e.g. 1994 → MCMXCIV). Supports 1–3999.
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Shoe Size Converter
Convert shoe sizes instantly between US (men/women/kids), UK, EU and Japanese sizing. Enter your foot length or a known size to see all systems at once.
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Temperature Converter
Convert between °C, °F, K and °Rankine all at once, with a visual thermometer marking freezing, body temperature, boiling and oven heat. Free and instant.
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Unit Converter
Convert any unit instantly: metres, feet, kilograms, pounds, litres, gallons, m², acres, km/h, mph and more — all in one free universal converter.
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Video File Size Calculator
Calculate video file size from bitrate and duration, or find the bitrate for a target size. Compare 720p, 1080p and 4K storage requirements instantly.
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