How many gallons of water in a 18x4 ft pool?

```

V = L x W x D

```

where:

* V is the volume in cubic feet

* L is the length of the pool in feet

* W is the width of the pool in feet

* D is the depth of the pool in feet

In this case, the pool is 18 feet long, 4 feet wide, and 2 feet deep. So, the volume of the pool is:

```

V = 18 x 4 x 2 = 144 cubic feet

```

Since there are 7.48 US gallons in 1 cubic feet, the pool can hold around:

```

V = 144 / 7.48 = 19.275 US gallons

```