Can guppies live with crayfish?

Verdict
Yes

Yes. Guppies and crayfish get along in the same tank. Both are fine at 72–77°F. Plan on at least 20 gal.

GuppyGuppy72–82°F · pH 6.8–7.8 CrayfishCrayfish65–77°F · pH 6.5–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–77°Guppy 72–82°Crayfish 65–77°
The green band is the temperature range both can live in.
456789Both: 6.8–7.8Guppy 6.8–7.8Crayfish 6.5–8
The green band is the pH both tolerate.

Size to scale

Guppy · 2 inCrayfish · 5 in0"1"2"3"4"5"6"
Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

GuppyCrayfish
Temperature72–82 °F65–77 °F
pH6.8–7.86.5–8
Adult size2.0 in5.0 in
Minimum tank10 gal20 gal
TemperamentPeacefulAggressive
Swims atTopBottom
GroupGroups of 3+One per tank
DietOmnivoreOmnivore

Better tank mates for guppies

All guppy tank mates

Better tank mates for crayfish

All crayfish tank mates

Questions

Can guppies live with crayfish?

Yes. Guppies and crayfish get along in the same tank. Both are fine at 72–77°F. Plan on at least 20 gal.

What temperature suits both guppies and crayfish?

72–77 °F. Guppies need 72–82 °F, crayfish need 65–77 °F.

What size tank do guppies and crayfish need together?

At least 20 gal, set by the crayfish. Add space for each extra fish.