Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Convert between length, weight, temperature, and volume units instantly.
Instead of hunting for a specific pairwise converter, this tool handles length, weight, area, and digital data units all in one place -- pick a category, pick your units, and get an instant result. It's the general-purpose option on this site; for a dedicated page around one specific, frequently-searched conversion (like acres to square feet), see the Converters category for a purpose-built version with deeper reference material.
Select a category (Length, Weight, Area, or Data), then choose your "from" and "to" units from that category's dropdown list, and enter your value. The result updates instantly.
Result = (Value × From Unit's Base Factor) ÷ To Unit's Base Factor
Each category has an internal "base unit" (meters for length, grams for weight, square meters for area, bytes for data) -- every unit in that category first converts to the base unit, then from the base unit to your target. This two-step approach is why any unit can convert to any other unit within the same category using just one set of constants per unit, rather than needing a separate formula for every possible pair.
| Category | Units |
|---|---|
| Length | mm, cm, m, km, in, ft, yd, mi |
| Weight | mg, g, kg, oz, lb, stones, metric tons |
| Area | sq mm, sq cm, sq m, sq km, sq ft, and more |
| Data | bytes, KB, MB, GB, and more (binary, base-1024) |
Quick everyday conversions that don't need a dedicated deep-dive page -- checking a weight in a different unit, converting a file size, or comparing area measurements. For a more detailed, example-rich treatment of a specific frequent conversion, see a dedicated tool like Pounds to KG or Acres to Square Feet.
Data storage units here use the binary (1024-based) convention common in computing (1 KB = 1024 bytes), not the decimal (1000-based) convention some storage manufacturers use for marketing capacity -- this is why a drive's advertised size can look slightly different from what your operating system reports.
To convert 5 miles to kilometers, the tool treats meters as the base unit: 5 miles is 5 x 1,609.344 = 8,046.72 meters, which is 8.04672 kilometers. To convert 12 stones to pounds, it uses grams as the base: 12 stones is about 76,203.5 grams, and dividing by 453.59237 gives roughly 168 pounds. For data, 2 gigabytes is 2 x 1024 x 1024 x 1024 bytes, or 2,147,483,648 bytes. Notice that the tool shows every unit in the chosen category at once, so a single entry gives you all equivalents without changing the dropdown repeatedly.
Result = value x (from-unit size in base units) / (to-unit size in base units)
The most frequent error is mixing linear and square units. A room that is 10 feet by 12 feet has an area of 120 square feet, not 120 feet. Converting 120 square feet to square meters requires the area category, and the answer is not the same as converting 120 feet to meters. Another mistake is assuming that a 1024-based data result will match a manufacturer's 1000-based label, which explains why the same drive can look different in different places. Finally, avoid comparing ounces of weight with fluid ounces of volume; they are different measurements even though the names are similar.
The conversion uses exact or standard constants for each unit, for example the international inch of exactly 25.4 millimeters, and shows a rounded result for readability. For everyday tasks, several decimal places are plenty. If you are working on engineering, construction cost estimates, or anything safety related, keep extra digits in your own calculations and round only at the end, or verify critical values against a specification or a licensed professional.
This converter does not include temperature or volume units. If you need those, or want a page that explains one particular conversion in depth, use a dedicated converter from the Converters category.
Storage manufacturers commonly advertise capacity using decimal (1000-based) units, while operating systems typically report binary (1024-based) units -- the same raw byte count looks like a smaller number under the 1024-based convention, which is what this converter uses.
No -- conversions only work within the same category (length to length, weight to weight, etc.), since units from different categories measure fundamentally different physical quantities.
No. The available categories are length, weight, area, and data. Use a dedicated temperature or volume converter for those.
They measure different things: length versus area. Compute the area first, for example width times length, then convert the area units.
They use standard published definitions, such as 1 inch equals 25.4 millimeters, and the display is rounded. Keep extra precision if you need to chain several calculations.
The stone is still used in some countries for body weight. One stone equals 14 pounds, and the converter shows it alongside metric and imperial units.
Reference: NIST Weights and Measures