There are some functions to convert time and BinDec etc in PHP but i feel that a whole bunch of functions are missing. for example Temperature Converting functions (eg. included). and for speed, mass, energy etc all of those.

# From Celsius

// To Fahrenheit
function celfar($c) {
return $c*1.8+32; }

// To Kelvin
function celkel($c) {
return $c+273.15; }

// To Rankine
function celran($c) {
return $c*1.8+491.67; }

// To R?aumur
function celrea($c) {
return $c*0.8; }

# From Fahrenheit

// To Celsius
function farcel($f) {
return ($f-32)*(5/9); }

// To Kelvin
function farkel($f) {
return ($f-32)*(5/9)+273.15; }

// To Rankine
function farran($f) {
return $f+459.67; }

// To R?aumur
function farrea($f) {
return ($f-32)*(4/9); }

# From Kelvin

// To Celsius
function kelcel($k) {
return $k-273.15; }

// To Fahrenheit
function kelfar($k) {
return ($k-273.15)*9/5+32; }

// To Rankine
function kelran($k) {
return $k*1.8; }

// To R?aumur
function kelrea($k) {
return ($k-273.15)*0.8; }

# From Rankine

// To Celsius
function rancel($r) {
return ($r*(5/9))-273.15; }

// To Fahrenheit
function ranfar($r) {
return $r-459.67; }

// To Kelvin
function rankel($r) {
return $r*(5/9); }

// To R?aumur
function ranrea($r) {
return ($r*(4/9))-218.52; }

# From R?aumur

// To Celsius
function reacel($re) {
return $re*1.25; }

// To Fahrenheit
function reafar($re) {
return $re*2.25+32; }

// To Kelvin
function reakel($re) {
return $re*1.25+273.15; }

// To Rankine
function rearan($re) {
return $re*2.25+491.67; }