Any unit, any zone, any currency
Converters
Convert units, time zones and supported currencies with exact factors, real IANA zones and current reference rates.
Length Converter
Convert millimeters to miles and everything between with exact international factors.
Weight Converter
Convert kilograms, pounds, ounces, stones and tons with exact factors.
Temperature Converter
Celsius, Fahrenheit and Kelvin converted with exact thermodynamic formulas.
Area Converter
Square meters, feet, acres, hectares and square miles with exact conversion factors.
Volume Converter
Liters, gallons, cups, fluid ounces and cubic measures — US customary included.
Time Converter
Seconds, minutes, hours, days, weeks, months and years converted exactly.
Speed Converter
km/h, mph, m/s, ft/s and knots converted with exact factors — no rounded shortcuts.
Time Zone Converter
Convert a time between any two IANA zones with automatic daylight-saving handling.
Currency Converter
Convert supported world currencies with a free hourly reference feed and resilient daily fallbacks.
Concrete Calculator
Estimate the cubic yards and cubic meters of concrete needed for a slab, rectangular footing, cylindrical column or stairs, with a configurable waste percentage and 80 lb / 60 lb bag estimates.
What this covers
Unit, time-zone and currency conversion with exact factors rather than rounded shortcuts: SI and international definitions for length, mass, temperature, area, volume, time and speed; the IANA database for zones; and a free hourly reference feed for money with daily fallback sources.
Which tool to use
The seven unit converters use exact or defined factors, so forward and reverse conversions agree. Time Zone Converter uses real IANA zones and daylight-saving rules. Currency Converter uses a free hourly reference feed with daily fallbacks and shows freshness clearly.
Frequently asked questions
Are the conversion factors exact?
Where an exact definition exists, yes: a pound is exactly 0.45359237 kg, an inch exactly 2.54 cm, a US gallon exactly 3.785411784 L. Nothing is rounded before the arithmetic, only for display.
Why is the currency converter different from the others?
Because an exchange rate is a market price, not a definition. It is fetched from published daily sources, cached briefly in your browser, and labelled with its snapshot date — and marked stale rather than silently shown as current when it ages.
Does the time zone converter handle daylight saving?
Yes. Each zone’s offset is resolved from the IANA database for the exact date you enter, so a summer conversion and a winter one differ where they should.