How much does an average mouse weigh? - briefly
A typical mouse weighs roughly 20–30 grams, with most laboratory specimens falling near the midpoint of this range. Wild house mice exhibit similar masses, though individual weights can vary slightly due to age, sex, and diet.
How much does an average mouse weigh? - in detail
The typical mass of a common house mouse (Mus musculus) falls between 15 g and 35 g when fully grown. Laboratory strains, bred for uniformity, usually weigh 20 g to 30 g as adults; the most frequently cited figure for a standard adult lab mouse is about 25 g. Wild individuals display a broader spectrum because of seasonal food availability, genetic diversity, and habitat conditions, with weights as low as 12 g during lean periods and up to 40 g when resources are abundant.
Key factors influencing the weight of a mouse:
- Sex: Males tend to be 10‑15 % heavier than females of the same age.
- Age: Juveniles gain weight rapidly during the first six weeks; growth plateaus after sexual maturity.
- Strain: Inbred laboratory lines (e.g., C57BL/6, BALB/c) differ by several grams; some strains are selected for larger size.
- Diet: High‑calorie chow can increase body mass by 5‑10 % compared with standard laboratory feed.
- Environment: Temperature, cage density, and stress levels affect metabolic rate and, consequently, body weight.
Measurement practices:
- Weighing is performed on a calibrated analytical balance with a precision of 0.01 g.
- Animals are usually measured in the morning after a brief acclimation period to reduce activity‑related fluctuations.
- For scientific reporting, the mean weight of a cohort is presented with standard deviation (e.g., 24.8 ± 1.6 g).
Conversion to other units: 1 g ≈ 0.035 oz; therefore, a 25‑g mouse equals roughly 0.88 oz.
In summary, an adult mouse generally weighs between 15 g and 35 g, with laboratory specimens clustering around 20‑30 g. Variations arise from sex, age, genetic background, nutrition, and environmental conditions, all of which are accounted for in precise weighing protocols.