You can see the full list of units currently accepted by LON-CAPA by clicking on the small blue question-mark symbol that appears whenever you get a response that the units you entered were not understood by the program. The following table is adapted from the LON-CAPA help file. Only units given in this table can be used, and only the symbols shown can be used when entering the units. For example, you must use "35 kg", not "35 kilograms". (Correct usage is also expected on exams and quizes.)

Combinations of Units

Products and powers must be entered in a way that the computer can understand. In addtion, the precedence of operations must be honored. Two common examples would be "kg*m/s^2" and "J/(g*K)". The last one could also be written as "J/g/K". (Once again, correct usage is also expected on exams and quizes.)

Physical Units Accepted by LON-CAPA

Base Units

name          symbol      comment

meter           m         length
kilogram        kg        mass
second          s         time
ampere          A         electric current
kelvin          K         thermodynamic temperature
mole            mol       amount of substance
candela         cd        luminous intensity


Prefix         symbol      factor

yotta            Y         10^{24}
zetta            Z         10^{21}
exa              E         10^{18}
peta             P         10^{15}
tera             T         10^{12}
giga             G         10^9
mega             M         10^6
kilo             k         10^3
hecto            h         10^2

deci             d         10^{-1}
centi            c         10^{-2}
milli            m         10^{-3}
micro            u         10^{-6}
nano             n         10^{-9}
pico             p         10^{-12}
femto            f         10^{-15}
atto             a         10^{-18}
zepto            z         10^{-21}
yocto            y         10^{-24}

Important SI Derived Units

name           symbol     description

radian          rad       plane angle
degree          deg       plane angle (Pi rad=180 deg)
steradian       sr        solid angle

newton          N         force
joule           J         energy, work, heat
watt            W         power, radiant flux
pascal          Pa        pressure, stress
hertz           Hz        frequency

coulomb         C         electric charge
volt            V         electric potential, electromotive force
ohm             ohm       electric resistance
farad           F         electric capacitance
henry           H         inductance
tesla           T         magnetic flux density
weber           Wb        magnetic flux

electronvolt    eV        energy
becquerel       Bq        activity (radioactive)
gray            Gy        absorbed dose (of radiation)
sievert         Sv        dose equivalent (dose equivalent index)

Derived Units commonly used in Chemistry

name           symbol     comment

litre           L         volume
gram            g         mass
calorie         cal       energy
atm             atm       standard atmosphere

Other Derived Units accepted by LON-CAPA

name           symbol     comment

pound           lb        mass
ounce           oz        mass
hour            hr        time
minute          min       time
day             day       time
year            yr        time
astroUnit       AU        mean distance earth to sun
inch            in        length
foot            ft        length
mile            mi        length
yard            yd        length
nautical_mile   n_mi      length, nautical mile (UK)
rood            rood      area, rood
acre            acre      area, acre
pound_force     lbf       force
dyne            dyn       force
bar             bar       pressure
mmHg            mmHg      pressure, millimeter of mercury
torr            torr      pressure
Btu             Btu       energy
ohm             ohms      electric resistance
ohm             Ohm       electric resistance
ohm             Ohms      electric resistance
siemens         S         electric conductance
lumen           lm        luminous flux
lux             lx        illuminance


The coded units are interpreted in the order of basic unit, derived unit, then prefix. For example, "min" will match "minutes" instead of being treated as a combination of the prefix "m" and the unit "in". Further, "T" by itself will always be matched against "tesla" instead of considered shorthand for 1012 (which would be improper usage in any case).