This list contains frequently encountered units but excludes SI base units.
| A | ampere (electric current) |
| Å | angstrom (10–1 nm distance; do not define unless specifically indicated) |
| A·h | ampere hour |
| AM | ante meridiem |
| A·s | ampere second |
| ATA | atmosphere absolute |
| atm | atmosphere |
| B | bel |
| Bq | becquerel (radioactivity) |
| bar | (no abbreviation) (105 Pa) |
| beats/min | beats per minute (heart rate; do not use bpm) |
| BeV | billion electron volts |
| bp | base pair |
| C | coulomb (electric charge) |
| °C | degree Celsius |
| cal | calorie |
| cd | candela (luminance) |
| Ci | curie |
| clo | reciprocal of thermal conductance |
| cmH2O | centimeter of water |
| counts/s | counts per second |
| cP | centipoise (viscosity) |
| cpm | counts per minute (define as counts/min) |
| cw | continuous wave |
| cycles/deg | cycles/degree (unit symbol is "°/s"; e.g., 15°/s) |
| cycles/min | cycle per minute |
| cycles/s | cycles/second (Hz) |
| D | debye; darcy |
| Da | dalton (molecular mass) |
| dB | decibel |
| deg or ° | degree (see above) |
| dpm | disintegrations per minute (define as disintegrations/min) |
| dyn | dyne |
| eq | equivalents |
| eV | electron volts |
| F | farad (electric capacitance) |
| ft | foot |
| ft.-cd | foot candle |
| ft.-L | foot lambert |
| G | gauss |
| G | gravitational constant |
| g | gravity (e.g., 1,000 g) |
| g·atom | gram·atom |
| g·cm | gram·centimeter |
| g·min | product of acceleration & time specifying speed & duration of centrifugation |
| g·mol | gram·molecule |
| gr | grain |
| Gy | gray (absorbed dose) |
| H | henry (electric inductance) |
| H–1 | reciprocal henry |
| hp | horsepower |
| Hz | hertz (cycles/s; frequency) |
| imp | impulse |
| in. | inch |
| in./s | inch per second |
| IU | international unit |
| J | joule (energy, work, quantity of heat) |
| K | Kelvin (use °K if there is risk of confusion with other variables) |
| kb | kilobase |
| kcal | kilocalorie (change Cal to kcal) |
| kgH2O | kilogram H2O (always bumped) |
| kg·m | kilogram·meter (work) |
| kpm | kilopond·meter (work) |
| L | lambert (watch out for " L" used incorrectly as "liter") |
| l | liter (volume; spell out when used alone) |
| lb. | pound |
| lb./in.2 | pound per inch squared (do not use psi) |
| lm | lumen (luminous flux) |
| lx | lux (illuminance) |
| M | molar (mM = millimolar = mmol/l) |
| mho | reciprocal Ω (change to S for siemens) (1/Ω) |
| m·L | meter lambert |
| mmHg | millimeters of mercury (always bumped) |
| mol/kg | mole per kilogram (molal) |
| mol/l | mole per liter |
| mph | mile per hour |
| MW·h | megawatt hour |
| N | normal |
| N | Newton (force) |
| N/s | Newtons per second (rate of force development) |
| N·s | Newtons times seconds (force) |
| N/m2 | newton per meter squared |
| N·m/deg | newton meter per degree |
| np | nepers (log of intensity ratio) |
| Ω | ohm (electric resistance) |
| osM | osmolar (osmolarity) |
| osmol/kgH2O | osmolal (osmolality; sometimes authors use mOsm — change to mosmol/kgH2O and query author) |
| oz | ounce |
| P | Poise |
| Pa | pascal (pressure, stress) |
| pack·yr | pack/day × years of smoking |
| PM | post meridiem (sm caps) |
| ppm | part per million |
| % | percent (no space; e.g., 10%) |
| R | roentgen |
| rad | absorbed dose of ionizing radiation |
| rad | radian (plane angle) |
| rpm | revolutions per minute (define as revolution/min) |
| rps | revolutions per second |
| S | Siemens (mho) (conductance) |
| spikes/s | spikes/second (don't abbrev. spikes) |
| slyke | millimole per pH unit |
| sr | steradian (solid angle) |
| Sv | sievert (dose equivalent) |
| t | metric ton (mass) |
| T | tesla |
| Torr | torr (equals 1 mmHg; in JAP, always use Torr, not mmHg, to express blood gas values such as PO2, PCO2, etc.) |
| U | units |
| u | atomic mass unit |
| V | volts (electrical potential, potential difference) |
| W | watt (power, radiant flux) |
| Wb | weber (magnetic flux) |
| W·h | watt·hour |
| z | atomic number |
| day | not abbreviated |
| h | hour |
| min | minute |
| mo | month |
| s | second |
| wk | week |
| yr | year* |
*When years is used in a historical context, do not abbreviate.
When an author uses "military time" (24-h clock; prevalent in Europe), do not change to 12-hour time. Delete the colon between the hours and minutes if one is used, and delete the abbreviation "h" for hours if it is present.
At 1800 we fed the animals with...
At 6 PM, the animals received an injection of...
The rats were exposed to light daily, between 0630 and 1830 (12-h light-dark cycle).
The following terms are spelled out when part of a sentence; however, they must be abbreviated when used after a number and/or a unit of measure, usually in the form of a dosage (e.g., "16 mg/kg iv").
| body wt | body weight |
| ia | intra-arterial |
| ic | intracutaneous |
| icv | intracerebroventricular |
| id | intradermal |
| im | intramuscular |
| ip | intraperitoneal |
| iv | intravenous |
| po | per os (oral) |
| sc | subcutaneous |
Methods of drug delivery may be abbreviated in text if they appear frequently. In such a case, they must be defined at first occurence. They do not require definition when used with numerical values and units. Note lack of periods after these abbreviations.
last edited 07/29/03