Who is faster: a horse or a mouse? - briefly
A horse can sprint up to roughly 55 mph, whereas a mouse’s top speed is about 8 mph; therefore the equine animal is considerably faster.
Who is faster: a horse or a mouse? - in detail
Horses achieve the highest recorded speeds among terrestrial mammals. A Thoroughbred racehorse can sustain 55 mph (≈ 88 km/h) over a furlong, with peak bursts reported near 70 mph (≈ 112 km/h). Muscular composition favors fast‑twitch fibers, and a long stride (≈ 2.4 m) allows rapid ground coverage. Efficient cardiovascular output supports the energy demand of sprinting.
House mice reach maximum velocities of about 8 mph (≈ 13 km/h). Their short limbs produce a stride of roughly 0.1 m, limiting distance per step. Although mice possess a high metabolic rate, the small body mass restricts absolute power output, confining sprint performance.
Key factors determining the disparity:
- Mass scaling – Power scales with muscle cross‑section, which increases faster than body mass, giving larger animals greater absolute force.
- Stride length – Longer limbs translate into greater distance per motion cycle.
- Fiber type distribution – Both species rely on fast‑twitch fibers, but the horse’s larger muscle mass yields higher total force.
- Aerobic capacity – Larger cardiovascular systems deliver more oxygen to muscles during high‑intensity effort.
Consequently, the equine athlete outruns the rodent by a factor of roughly ten, confirming that the horse is the faster of the two.