How much does a mouse weigh on average? - briefly
A common house mouse typically weighs between 20 g and 30 g (0.7–1.1 oz). Laboratory strains are usually slightly lighter, averaging 18 g to 25 g.
How much does a mouse weigh on average? - in detail
The average adult laboratory mouse typically weighs between 20 and 30 g (0.7–1.1 oz). Female specimens are usually at the lower end of this range, while males tend toward the higher end. Weight varies with strain; for example, C57BL/6 mice commonly fall near 25 g, whereas larger strains such as BALB/c can reach 30 g.
Wild mice exhibit broader variability. House mice (Mus musculus) captured in temperate regions often weigh 15–25 g, whereas individuals from resource‑rich environments may exceed 30 g. Seasonal changes affect body mass: higher food availability in summer leads to increased weight, while winter scarcity can reduce it by several grams.
Key factors influencing mouse mass:
- Age: Juveniles under four weeks weigh less than 10 g; adult weight stabilizes after eight weeks.
- Diet: High‑calorie chow raises average weight by 2–4 g compared with standard rodent feed.
- Health status: Pathologies such as obesity or malnutrition cause measurable deviations from the norm.
- Housing conditions: Group housing can promote social hierarchy effects on feeding, altering individual weights.
Measurement practice recommends using a calibrated analytical balance with a precision of 0.01 g. Record weight at the same time of day to minimize circadian fluctuations. For longitudinal studies, calculate the mean of three consecutive readings to improve reliability.
In summary, a typical mouse weighs roughly 20–30 g, with specific values dependent on genetics, environment, sex, and age. Accurate assessment requires standardized weighing procedures and awareness of the variables that can shift the average.