How to Choose the Right Geyser Size

Getting geyser size wrong in either direction costs you — too small and you’re constantly running out of hot water, too large and you’re paying to heat water you don’t use.

Start with household size

• 1-2 people: a 100-150 litre geyser is usually sufficient for typical use
• 3-4 people: 150-200 litres covers most households comfortably
• 5+ people, or homes with multiple bathrooms used simultaneously: 200-300 litres or a dual-geyser setup may be needed

Factor in actual usage patterns

A household where everyone showers within the same hour each morning needs more capacity than the same number of people showering at staggered times throughout the day. Baths use significantly more hot water than showers, so a home with a bath in regular use should size up.

Consider your appliances

If your dishwasher or washing machine draws from the hot water system rather than heating its own water internally, that adds to the demand your geyser needs to cover.

Solar and heat pump sizing is different

These systems are sized around both storage capacity and recovery rate (how fast they reheat), which depends on sun exposure or the heat pump’s output rating — not just litres alone.

When in doubt, get it assessed

A plumber can look at your household’s actual usage — number of bathrooms, typical routine, appliances — and recommend a size based on real demand rather than a generic rule of thumb. Getting this right the first time avoids both the frustration of cold showers and the ongoing cost of an oversized tank.