Free Online Converters: Unit, Currency & Measurement Converter Tools

All-in-one unit converter tools (40 free converters)

This hub brings together 40 free online converters in one place. Whether you need a quick unit converter for a school assignment, a measurement converter for a DIY project, or a conversion calculator for work, every tool here runs instantly in your browser. There is no signup, no download, no daily limit, and nothing is uploaded to a server.

Each converter uses scientifically established SI conversion factors, so the results are precise and dependable. The hub pages cover an entire family of units at once, while dedicated pages handle the single most-searched pairs like kg to lbs, cm to inches, and Celsius to Fahrenheit. Pick the broad tool when you want flexibility, or the focused tool when you want the answer fast.

Weight and mass converters (kg, lbs, grams, ounces, tola)

Weight conversion is the most-searched category here. The weight converter handles kilograms, pounds, grams, ounces, stone, and tola in a single tool, while focused pages cover the exact pairs people look up most. To convert kg to lbs you multiply by 2.2046, so 70 kg equals 154.3 lbs; to go back, the lbs to kg tool divides by the same factor.

For the kitchen and nutrition labels, the grams to ounces and ounces to grams tools use the standard 1 ounce = 28.3495 grams. Jewelry and gold buyers in South Asia rely on the tola, where 1 tola weighs about 11.6638 grams in the traditional trade. Every weight tool includes a reference chart so you can sanity-check a result at a glance.

Length and distance converters (cm, inches, feet, meters, km, miles)

The length converter switches between meters, feet, inches, centimeters, kilometers, miles, and yards in one place. The inch is defined as exactly 2.54 cm, which makes cm to inches and inches to cm fully reversible with no rounding error. For height, the cm to feet and feet to cm tools convert into the familiar feet-and-inches format used across the US.

Distance and travel queries are covered by km to miles and miles to km, where 1 mile equals 1.609344 km. Engineering and construction work usually needs feet to meters, where 1 foot is exactly 0.3048 m, and meters to feet for the reverse. Each tool ships with a quick-reference table for the values people look up most often.

Temperature converters (Celsius, Fahrenheit, Kelvin)

Temperature is the one category where you cannot just multiply by a factor, because the scales have different zero points. The temperature converter shows Celsius, Fahrenheit, and Kelvin side by side and recalculates all three as you type. To convert Celsius to Fahrenheit the formula is F = (C x 9/5) + 32, so 100 C equals 212 F, the boiling point of water.

Going the other way, Fahrenheit to Celsius uses C = (F - 32) x 5/9. For science and photography color temperature, Celsius to Kelvin simply adds 273.15, and Kelvin to Celsius subtracts it. The dedicated pages add practical references like oven temperatures, weather ranges, and the normal human body temperature of 37 C, which equals 98.6 F.

Area, volume, speed, pressure, and energy converters

Beyond the basics, the hub covers the units that come up in property, cooking, travel, and engineering. The area converter handles square feet, square meters, acres, hectares, and the South Asian Marla and Kanal. The volume converter switches between liters, US and UK gallons, cups, tablespoons, and fluid ounces, which matters because a US gallon (3.785 L) is smaller than a UK gallon (4.546 L).

The speed converter compares km/h, mph, m/s, knots, and Mach, useful for driving, aviation, and weather. The pressure converter covers PSI, bar, pascals, atmospheres, and mmHg for tyres, diving, and lab work. The energy converter moves between calories, joules, watt-hours, kilowatt-hours, and BTU, so you can read a nutrition label or a utility bill in whichever unit you prefer.

Data storage, cooking, and fuel economy converters

The data storage converter translates between bytes, kilobytes, megabytes, gigabytes, terabytes, and bits, using the binary 1024-based system that operating systems actually report. It is the fastest way to check whether a download will fit on a drive or stay under an upload limit.

For recipes, the cooking converter moves between cups, tablespoons, teaspoons, and milliliters in both US and metric measures, so a recipe written for one region works in your kitchen. The fuel economy converter handles the tricky non-linear math between MPG (US and UK), L/100km, and km/L, letting you compare a car spec sheet across markets without getting the inverse relationship wrong.

Live currency converter and popular pairs

The currency converter supports 38+ currencies with live exchange rates that refresh hourly, so the number you see reflects the current market rather than a stale snapshot. Enter an amount, choose your two currencies, and the converted value appears instantly. It is built for travelers, freelancers paid in foreign currency, and online shoppers comparing prices across borders.

Dedicated pages cover the pairs with the heaviest demand, especially for the South Asian and Gulf-expat audience: USD to PKR, SAR to PKR, AED to PKR, GBP to PKR, and EUR to PKR all show the live Pakistani Rupee rate, while USD to INR tracks the Indian Rupee and USD to BDT the Bangladeshi Taka. Because these rates move every day, the converter always pulls the latest figure rather than a fixed number.

South Asian and regional unit converters (Marla, Kanal, Tola)

Standard converters often ignore the units that South Asian users actually buy and sell with, so Gizmoop adds them explicitly. The Marla to square feet tool converts Pakistani plot sizes between Marla, Kanal, acre, and square feet. In revenue and rural land records 1 Marla equals 272.25 square feet and 1 Kanal equals 20 Marla, although many urban housing schemes use a rounded 225 square feet per Marla.

For gold and jewelry, the tola is the everyday weight unit across Pakistan and India. The tola to grams converter uses the traditional trade value of 1 tola = 11.6638 grams, the figure most local jewelers price against, while noting that some metric definitions round it to 11.66 or 12.5 grams. Knowing which definition a seller uses helps you check a quote before you buy.

Timezone converter

The timezone converter is a meeting planner for people working across borders. Pick two or more cities and it lines up their local times so you can find a slot that works for everyone, with daylight saving time handled automatically so you never miscalculate an hour in spring or autumn.

It is especially handy for remote teams, expat families staying in touch, and anyone scheduling a call between Pakistan, the Gulf, Europe, and North America. Because DST rules differ by country and change over the year, an automatic converter is far safer than doing the offset arithmetic in your head.

Most-searched conversions

A handful of conversions account for the bulk of everyday lookups, so they each get a dedicated, fast-loading page. Kg to lbs and lbs to kg lead the list for body weight and shipping. Cm to inches and inches to cm cover height and screen sizes. Celsius to Fahrenheit and Fahrenheit to Celsius handle weather, cooking, and fevers.

Rounding out the top set are km to miles and miles to km for running and road trips, feet to meters and meters to feet for construction, and grams to ounces and ounces to grams for the kitchen. Each page leads with the answer and the formula, then adds a conversion chart, so you get the value instantly and can verify it without leaving the tab.

What a unit converter is and how to convert online

A unit converter is a tool that takes a quantity expressed in one unit and rewrites it in another without changing the underlying value. It does this by applying a fixed conversion factor (for most units) or a formula (for temperature and fuel economy). Because the factors come from international SI definitions, a good converter is just as accurate as doing the math by hand, only faster and without arithmetic slips.

Converting online with Gizmoop takes three steps: type the value you have, choose the unit you are converting from, and choose the unit you want the result in. The answer appears instantly as you type, with no calculate button and no waiting. There is nothing to install and no account to create, so the same workflow works on a phone, tablet, or desktop.

Metric versus imperial is the source of most confusion. Most of the world uses the metric system (meters, kilograms, Celsius), while the US sticks largely with imperial units (feet, pounds, Fahrenheit). A converter bridges the two automatically, which is why these tools are most popular wherever the two systems meet, in international shipping, travel, science, and online shopping.