> ## Documentation Index
> Fetch the complete documentation index at: https://calcs.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# How to Use Formulas and Convert Units in Inputs
> How to Use Formulas and Convert Units in Inputs
Just like in Excel, Calcs.com lets you perform quick calculations inside any input cell. Unlike Excel however, Calcs.com also lets you type units and converts them on the fly! All you need to do is enter the mathematical operation you want, and you can include any units you'd like!
# Use a Formula
1. Simply start typing a formula into any input field
2. Type in your preferred formula (for example $= 5 \cdot 1500$)
3. Calcs.com will automatically perform the calculation, including
*See it in action*
# Convert Units
*Note: This article is about converting units in an input. If you'd like to change the unit system for your entire project, including in all the output numbers, see the article* [*How to Change Unit Systems*](/learn_calcs/advanced_tricks/how_to_change_units)
Units may be used in any input field. You can even perform calculations with units, such as
```math theme={null}
EI = 200 GPa \cdot 50.0e6 mm^3
```
Calcs.com recognises hundreds of different types of units, and if you're using the metric system, all the standard SI prefixes (u, m, c, k, M, G, etc.). Some examples of common units are listed below, but many others are also available - if you want to enter a length in "rods" or a volume in "teaspoons", you can do that too! First, a few general notes:
* You can type either the full name of a unit or just its abbreviation
* You may optionally include an "s" at the end of a unit (e.g. "lb" and "lbs" are the same thing)
* For multiplied units, such as units of moment, you may use the multiplication symbol "\*" or simply insert a space between the units (e.g. "kN m" or "kN\*m" are the same thing)
* Be cautious about "Mass" versus "Force or Weight" (especially in the Imperial system, where both units are confusingly called "pounds"). Weight is equal to Mass times the force of gravity, which you can convert in Calcs.com as, for example, "5 kg \* gravity" ("gravity" is a constant equal to 32.18 ft/s^2 or 9.807 m/s^2)
| Unit Type | Metric Units | Imperial Units |
| ---------------- | ------------------------------------------- | ------------------------------------------------------------ |
| Length | meter (m) | mil, inch (in), foot (ft), yard (yd) |
| Surface Area | $m^2$, $mm^2$, $cm^2$,
| $mil^2$ (sqmil), $in^2$ (sqin), $ft^2$ (sqft), $yd^2$ (sqyd) |
| Volume | $m^3$, $mm^3$, $cm^3$ (cc), litre (L)
| $mil^3$, $in^3$ (cuin), $ft^3$ (cuft), $yd^3$ (cuyd) |
| Angles | degree (deg), radian (rad)
| degree (deg), radian (rad)
|
| Mass | gram (g), kg, tonne
| ton, ounce (oz), poundmass (lbm) |
| Force or Weight | newton (N), kN, MN | poundforce (lb\* or lbf), kip |
| Moment | N m, kN m, N mm | lb ft, lb in, kip in |
| Pressure | Pa, kPa, MPa, GPa | psi, ksi\*, psf, ksf\* |
| Mass Density | kg/$m^3$, g/$mm^3$ | lbm/$in^3$, lbm/$ft^3$, oz/$in^3$ |
| Weight Density | N/$m^3$, kN/$m^3$ | lb/$in^3$ (pci\*), lb/$ft^3$ (pcf\*), kip/$ft^3$ (kcf\*) |
| Force per Length | N/m, kN/m, N/mm, kN/mm | lb/ft (plf\*), kip/ft (klf\*) |
| Temperature | celsius (degC), kelvin (K) | fahrenheit (degF), rankine (degR) |
| Time | second (s), hour (h or hr), day, year | second (s), hour (h or hr), day, year |
\* All units except those marked with asterisk (\*) are also described in [MathJS documentation](https://mathjs.org/docs/datatypes/units.html) , where you can find a complete list of all other units available.