UK vs US spelling

Back to style guide

US spelling UK spelling/usage
or → our                           favor behavior                                   favour behaviour
color colour, but coloration, colorimetry, decolorise, discoloration
tumor tumour, but tumoral
humor humour (fluid), but humoral, humorally
er → re fiber fibre (but filter)
titer titre
liter litre
meter metre (unit) but meter for measuring device. Note also diameter
caliber calibre
center centre (except in US addresses and others officially spelled with '… er', e.g. Steno Diabetes Center
l → ll labeled labelled
signaled signalled
modeled modelled
equaled equalled
f → ph sulfur sulphur
e → oe apnea apnoea
diarrhea diarrhoea
eosophageal oeosophageal
estrogen oestrogen
maneuver manoeuvre
e → ae endotoxemia endotoxaemia
dyslipidemia dyslipidaemia
hyperglycemia hyperglycaemia
hemoglobin haemoglobin
ischemia ischaemia
anesthetised anaesthetised
etiology aetiology
uremia uraemia
pediatric paediatric (but pedagogic)
fecalfaecal
log → logue homolog homologue
catalog catalogue
analog analogue
s → c defense defence
offense offence
practise Verb: practise; noun: practice
license Verb: license; noun: licence
lyz → lys analyzed analysed
dialyzed dialysed
catalyzed catalysed
ic → ical biologicbiological
pathologic pathological
physiologic physiological
Miscellaneous aging ageing
aluminum aluminium
artifact artefact
billion 1000 million
different than different from
drug store pharmacy (medicines obtainable on or off prescription)/chemist (incorporates pharmacy but also sells toiletries)
EKG ECG
fall autumn
gray grey
fulfill fulfil
guinea pig guinea-pig
leukocyte leucocyte
mold mould
operating room operating theatre
program programme (except for computer program)
skillfull skilful
toward towards

Back to top

Back to style guide