Conversions
Metric Prefixes
| Prefix | Symbol | Meaning | Prefix | Symbol | Meaning |
|---|---|---|---|---|---|
| quetta | $Q$ | $10^{30}$ | quecto | $q$ | $10^{-30}$ |
| ronna | $R$ | $10^{27}$ | ronto | $r$ | $10^{-27}$ |
| yotta | $Y$ | $10^{24}$ | yocto | $y$ | $10^{-24}$ |
| zetta | $Z$ | $10^{21}$ | zepto | $z$ | $10^{-21}$ |
| exa | $E$ | $10^{18}$ | atto | $a$ | $10^{-18}$ |
| peta | $P$ | $10^{15}$ | femto | $f$ | $10^{-15}$ |
| tera | $T$ | $10^{12}$ | pico | $p$ | $10^{-12}$ |
| giga | $G$ | $10^{9}$ | nano | $n$ | $10^{-9}$ |
| mega | $M$ | $10^{6}$ | micro | $\mu$ | $10^{-6}$ |
| kilo | $k$ | $10^{3}$ | milli | $m$ | $10^{-3}$ |
| hecto | $h$ | $10^{2}$ | centi | $c$ | $10^{-2}$ |
| deka | $da$ | $10^{1}$ | deci | $d$ | $10^{-1}$ |
| (base unit) | - | $10^{0}$ | (base unit) | - | $10^{0}$ |
Conversions
Length
$\begin{aligned} 1 \:m &= 39.37( \approx 243/8) \:in &&= 3.28( \approx 105/32) \:ft &&= 1.094( \approx 11/10) \:yd \\ 1 \:in &= 2.54 \:cm &&= 1/12 \:ft \\ 1 \:ft &= 12 \:in &&= 0.3048 \:m \\ 1 \:km &= 0.6214 \:mi &&= 3281 \:ft \\ 1 \:mi &= 5280 \:ft &&= 1.609 \:km \\ 1 \:\text{light-year} &= 9.461 \times 10^{12} \:km \end{aligned}$
Temperature
$\begin{aligned} \text{Kelvin, } & K &&= {}^\circ C + 273.15 \\ \text{Celsius, } & {}^\circ C &&= K - 273.15 &&= \dfrac{5}{9}({}^\circ F - 32) \\ \text{Fahrenheit, } & {}^\circ F &&= \dfrac{9}{5}{}^\circ C + 32 \\ \text{Rankine, } & {}^\circ R &&= {}^\circ F + 459.67&&= \dfrac{5}{9}K \end{aligned}$
Speed
$\begin{aligned} km/h &= \dfrac{5}{18} \:m/s , & m/s &= \dfrac{18}{5} \:km/h \\ mi/h &= 0.447 \:m/s , &ft/s &= 0.305 \:m/s \\ \end{aligned}$
Mass
$\begin{aligned} 1 \:kg &= 2.204 \:lb &&= 35.274 \:oz \\ 1 \:lb &= 0.4536 \:kg &&= 16 \:oz \\ 1 \:oz &= 0.0283 \:kg \\ 1 \:amu &= 1.66 \times 10^{-27} \:kg \end{aligned}$
Force
$\begin{aligned} 1 \:N &= 10^5 \:dyn &&= 0.2248 \:lbf \\ 1 \:dyn &= 10^{-5} \:N \\ 1 \:lbf &= 4.448 \:N \end{aligned}$
Area
$\begin{aligned} 1 \:m^2 &= 10.764 \:ft^2 &&= 1550 \:in^2 \\ 1 \:in^2 &= 6.45 \:cm^2 \\ 1 \:acre &= 4047 \:m^2 &&= 43560 \:ft^2 \\ 1 \:hectare &= 10^4 \:m^2 \\ 1 \:mi^2 &= 2.59 \:km^2 &&= 640 \:acres \end{aligned}$
Volume
$\begin{aligned} 1 \:m^3 &= 10^3 \:L &&= 35.315 \:ft^3 &&= 264.2 \:gal \\ 1 \:cm^3 &= 1 \:mL &&= 0.061 \:in^3 \\ 1 \:L &= 10^3 \:cm^3 &&= 0.264 \:gal \\ 1 \:ft^3 &= 7.48 \:gal &&= 28.317 \:L \\ 1 \:gal &= 3.785 \:L &&= 231 \:in^3 \end{aligned}$
Pressure
$\begin{aligned} 1 \:kPa &= 10^3 \:N/m^2 &&= 10^{-2} \:bar &&= 9.87 \times 10^{-3} \:atm \\ 1 \:atm &= 101.325 \:kPa &&= 1.013 \:bar &&= 760 \:\text{mmHg (Torr)} \\ 1 \:bar &= 10^2 \:kPa &&= 14.5 \:psi \\ 1 \:psi &= 6.895 \:kPa \\ 1 \:\text{Torr} &= 0.133 \:Pa && (\vec{g} = 9.80665 \:m/s^2) \end{aligned}$
Work/Heat
$\begin{aligned} 1 \:J &= 624.15 \times 10^{10} \:MeV &&= 10^7 \:erg \\ 1 \:eV &= 1.602 \times 10^{-19} \:J \\ 1 \:cal &= 4.184 \:J \\ 1 \:Btu &= 1055 \:J \\ 1 \:\text{kWh} &= 3.6 \times 10^6 \:J &&= 3412 \:Btu \end{aligned}$
Power
$\begin{aligned} 1 \:W &= 1 \:J/s &&= 0.7376 \:ft \cdot lbf/s \\ 1 \:hp &= 745.7 \:W \end{aligned}$
Angle
$\begin{aligned} 1^\circ \text{ (degree)} &= \dfrac{\pi}{180} \:\text{rad} &&= 0.01745 \:\text{rad} \\ 1^\circ &= 60'\text{ (minutes)} \\ 1' &= 60''\text{ (seconds)} \\ 1 \:\text{rad} &= \dfrac{180^\circ}{\pi} \: &&= 57.30^\circ \\ 1 \:\text{revolution} &= 360 \:{}^\circ &&= 2 \pi \:\text{rad} \\ 1 \:\text{rev/min (rpm)} &= 0.1047\:\text{rad/s} \end{aligned}$