Capacon - Volume Unit Converter
Capacon is a small, focused converter for volume and capacity. You type a number, choose the unit you have and the unit you want, and the answer appears immediately underneath, along with a one-unit reference line such as "1 L = 1000 mL". There are no menus to dig through and nothing to sign up for.
It is handy whenever two people describe the same amount differently: a recipe written in liters while your measuring jug shows milliliters, a lab protocol that mixes microliters and milliliters, a water tank rated in cubic meters while the bill speaks of kiloliters, or a product label in US gallons. Because it covers both the everyday units and the very large and very small ones, it saves you from counting zeros by hand.
The web version runs entirely in your browser. Nothing you type is sent anywhere, and it works the same on a phone, tablet or computer.
The app runs entirely in your browser. What you enter is saved only on this device.
How to use Capacon
- Enter a value. Type the amount into the field at the top. The result updates while you type, so there is no Convert button to press. The clear (x) button empties the field.
- Pick the unit you have. Tap the "From" card and choose a unit from the list, for example Liter (L).
- Pick the unit you want. Tap the "To" card and choose the target unit, for example Milliliter (mL).
- Read the result. The large number in the Result card is your converted value. The small line below it shows what one unit of the source equals, which is useful for checking the scale.
- Swap or copy. The round arrow button between the two cards swaps the units. The copy icon in the Result card puts the converted value on your clipboard so you can paste it elsewhere.
- Use quick input. The Quick input row offers common amounts (0.1, 0.5, 1, 5, 10, 50, 100) that fill the field with one tap.
- Look up a unit. Open the Unit info tab to see each unit with a short explanation of what it is and where it is typically used.
Features
- Nine volume units: cubic meter, cubic decimeter, cubic centimeter, liter, milliliter, microliter, kiloliter, hectoliter and US gallon
- Results update instantly as you type
- One-tap swap between the source and target unit
- Copy the converted value to the clipboard
- Quick input buttons for common amounts
- A reference line showing what one unit equals
- A short list of recently used unit pairs during your visit
- Unit info tab with plain-language descriptions
- Interface available in many languages; add ?lang=ja (or another code) to the address to choose one
Understanding volume units
Everything in the metric system is a power of ten
Metric volume units are built from two ideas: the liter and the cube of a length. One liter is defined as exactly one cubic decimeter, a cube 10 cm on each side. That single fact explains most conversions. A milliliter is a thousandth of a liter, and because a cubic centimeter is a thousandth of a cubic decimeter, one milliliter equals one cubic centimeter exactly. Doctors write cc, engineers write cm³, cooks write mL, but they all mean the same amount.
Going the other way, a cubic meter is a cube one meter on each side. Each side is ten decimeters, so the cube holds 10 × 10 × 10 = 1000 liters. That is why water utilities often bill in cubic meters and why one cubic meter is also one kiloliter. A hectoliter, 100 liters, is common in brewing and wine making, while the microliter (a millionth of a liter) is the everyday unit of pipettes in laboratories.
Why cubes make conversions tricky
The most common mistake is to treat volume like length. There are 100 centimeters in a meter, but there are 1,000,000 cubic centimeters in a cubic meter, because you multiply by 100 three times. When a conversion seems off by a factor of a thousand or a million, this is usually the reason. A converter removes the guesswork, but it helps to know the rough size: a cubic meter of water weighs about a tonne, a liter about a kilogram, a milliliter about a gram.
Gallons are not all the same
The US gallon is defined as 231 cubic inches, which is about 3.785 liters. The imperial gallon used historically in the United Kingdom and some Commonwealth countries is larger, about 4.546 liters. Recipes, fuel figures and aquarium sizes from different countries can therefore disagree by roughly 20 percent if you assume the wrong gallon. Capacon's gallon is the US gallon, so check which one your source means before converting.
US customary units also divide differently from metric ones: a gallon is four quarts, a quart is two pints and a pint is two cups. When a recipe moves between systems, it is often easier to convert the total to milliliters once and then measure, rather than chaining several smaller conversions.
Practical tips
Keep an eye on significant figures. Converting 0.5 gallons to milliliters gives a long decimal, but a kitchen jug is only accurate to a few milliliters, so rounding is fine. In a lab, keep the precision your instrument actually has. When you share a converted value, mention the unit symbol clearly; mL and ML (megaliter) differ by a factor of a billion.
Frequently asked questions
Is the converter free to use in the browser?
Yes. Open the page and start typing; there is no account or sign-in.
Where is my data stored?
Capacon does not store your conversions. The recent unit pairs list only lasts while the page is open, and nothing you type is sent to a server. If you clear your browser data, nothing of value is lost.
Is a milliliter the same as a cubic centimeter?
Yes, exactly. One liter is one cubic decimeter, so one thousandth of each, the milliliter and the cubic centimeter, are identical.
Which gallon does Capacon use?
The US liquid gallon, about 3.785 liters. The imperial gallon (about 4.546 liters) is not included.
Can I change the language?
The app follows your browser language. To pick one yourself, add ?lang= and a language code to the page address, for example ?lang=ja for Japanese or ?lang=de for German.
How is the web version different from the phone app?
The conversions are the same. The iPhone and Android apps add an optional ad-free upgrade and store rating shortcuts, which are not part of the web version.
Limitations of the web version
- Only nine units are included; cups, pints, quarts, fluid ounces and the imperial gallon are not available
- Recently used unit pairs are forgotten when you close or reload the page
- Results are calculated with standard floating-point arithmetic, so very long decimals may show tiny rounding differences
Phone app
Capacon is also available as an app for phones and tablets: