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Reviewed by Alex Chen & Morgan Webb Updated June 30, 2026

Water heater sizing Last reviewed June 30, 2026

What Size Water Heater for a Family of 5?

By the WhatSize editorial team 4 min read Standards-reviewed

TL;DR

A family of 5 needs a 60-80 gallon storage tank water heater. If you choose tankless, you need a unit rated for 7.5+ GPM like the Rinnai RU160iN.

Looking for a different size? See What Size Water Heater for a 1-2 Person Household? or browse all water heater sizing guides.

Large Families Need Large Tanks

With 5+ people, hot water demand peaks in the morning when multiple showers, dishwashing, and laundry can happen simultaneously. A 60-gallon tank provides about 65 gallons of hot water in the first hour — enough for 3-4 showers plus kitchen use. For homes with 5+ people and a large soaking tub, an 80-gallon tank is the safer choice.

Large families should strongly consider a tankless water heater. The Rinnai RU160iN provides 7.5 GPM — enough for 2-3 simultaneous showers — and never runs out of hot water. The trade-off is higher upfront cost but lower operating costs.

Top picks for this size

AO Smith GPHE-50 Water Heater with Residential High Efficiency Power Vent Natural Gas #ad
★★★★★ 5 · 5 · $3685
Amazon
Rheem PROG50-36P RH62 Professional Classic Tall Residential 36K BTU Atmospheric Liquid Propane Gas Water Heater, 50-Gallon #ad
★★★★ 4.4 · 4 · $915
Amazon
Rheem PROG50-42N RH67 PV Professional Classic Residential 42K BTU Power Vent Natural Gas Water Heater, 50-Gallon #ad
★★★★ 4.4 · 3 · $2042
Amazon
Bradford White RE350S6-1NCWW Bwc 50Gal 240V #ad
★★★★☆ 4.6 · 4 · $1295
Amazon
Rheem PROE50 M2 RH95 50-Gallon Professional Classic Medium Residential Electric Water Heater, Gray; Enhanced-flow Brass Drain Valve; 18.75 Amps; Automatic Thermostat; Anode Rod #ad
★★★★☆ 4.6 · 6 · $940
Amazon
ACiQ Electric Residential Hybrid Hot Water Heater Electric 50 Gallon Tank | Heat Pump, Water Heater, Quiet Operation | 240V, 1Ph, 60Hz #ad
★★★★ 4.4 · 6 · $1800
Amazon
Rinnai REHP50 Electric Heat Pump Water Heater – 50 Gallon, 240V, 30A, Energy Star Certified, 3.75 UEF, 73 Gallon First Hour Delivery for Residential Use #ad
★★★★☆ 4.9 · 4 · $1799
Amazon
Rinnai REHP65 Electric Heat Pump Water Heater‚ 65 Gallon, 240V, 30A, Energy Star Certified, 3.90 UEF, 80 Gallon First Hour Delivery for Residential Use #ad
★★★★☆ 4.9 · 4 · $2049
Amazon
MRCOOL 50 Gallon Electric Water Heater 4500W Tank, High Efficiency Dual Element, Self Cleaning, Rare Earth Anode, 240V Home Use, Gray #ad
★★★★☆ 4.9 · 1 · $930
Amazon
Senville 50 Gallon (189L) Hybrid Heat Pump Electric Water Heater, 4.5kW High Efficiency Tank, Energy Star® #ad
★★★★☆ 4.9 · · $1200
Amazon

These Amazon-available picks meet the calculated spec. For region-specific or licensed contractor-installed options, consult a local professional. See our Disclaimers.

Best Options for Large Families

  • Storage tank (60 gal): Rheem Performance 60 Gal (~$629) — 12-year warranty
  • Storage tank (80 gal): Rheem Performance 80 Gal (~$899) — maximum capacity for large families
  • Tankless gas: Rinnai RU160iN (~$1,299) — unlimited hot water, 20-year warranty

Frequently asked questions

What size water heater for a family of 5?

A 50-gallon tank will struggle with 5 people. You'll experience cold showers during peak usage. Step up to at least 60 gallons or go tankless.

How long do water heaters last?

Storage tank water heaters last 8-12 years with proper maintenance (annual flushing, anode rod replacement). Tankless units last 15-20+ years. Hybrid heat pump units typically last 10-15 years.

Still choosing between sizes? Compare: tank vs tankless

Need a more precise recommendation?

Use our interactive calculator — it adjusts for household size, morning showers, and tank vs. tankless.

Try the Water heater calculator