Most small hot tubs are approximately 3 feet high, 6 feet wide and 5 feet long, holding about 300 gallons of water. Large hot tubs, which can fit up to eight people or more, are usually about 4.5 ...

but tubs vary in size, holding 25-150 gallons of water or more. Make sure your water heater is large enough to fill about two-thirds of your tub with warm water. Related: How Much Does It Cost to ...