How much does a domestic mouse weigh? - briefly
A typical house mouse weighs between 20 g and 30 g, averaging about 25 g.
How much does a domestic mouse weigh? - in detail
The domestic mouse (Mus musculus domesticus) typically falls within a narrow mass interval that reflects its developmental stage, sex, genetic background, and husbandry conditions. Newborn individuals weigh approximately 1–2 g. Juveniles increase rapidly, reaching 10–15 g by four weeks of age. Fully mature adults usually weigh between 15 g and 30 g, with the upper extreme of healthy individuals approaching 45 g under optimal nutrition.
Several variables modify the average weight:
- Sex – males are on average 2–4 g heavier than females of the same strain.
- Strain – laboratory inbred lines such as C57BL/6 maintain a consistent adult weight of 20–25 g, whereas outbred stocks may display broader variability.
- Diet – high‑calorie pelleted feed can raise adult mass by 5–10 % compared with standard maintenance rations.
- Environmental enrichment – cages equipped with nesting material and exercise devices tend to produce slightly heavier specimens due to increased muscle development.
Pet mice, which are often selected for robust health and aesthetic traits, commonly fall in the 25–35 g range. In contrast, research colonies that prioritize uniformity may restrict adult weight to a tighter 18–22 g window to reduce experimental variance.
Accurate weighing requires a calibrated analytical balance with a resolution of at least 0.01 g. Animals should be weighed in a calm state, preferably in a clean, low‑stress container, and measurements recorded to the nearest hundredth of a gram. Repeated readings over consecutive days improve reliability and account for transient fluctuations in gut contents.
In summary, the mass of a house mouse varies from roughly one gram at birth to a maximum of forty‑five grams in adulthood, with the most frequent adult weight lying between fifteen and thirty grams, contingent upon genetic line, sex, diet, and housing conditions.