A 50 gallon water heater comfortably serves a household of 3–4 people and is the most popular default size, while a 40-gallon tank suits 2–3 people and a 75-gallon tank fits homes of 5 or more. The right choice comes down to how many people use hot water at the same time, not just the number of bathrooms.
Here is what this guide covers:
- The real difference between a 40 and 50 gallon tank
- How many people each size supports
- When it makes sense to size up
- The cost and energy difference (smaller than you think)
Beyond the 10 extra gallons of storage, the bigger factor is First Hour Rating (FHR) — how much hot water the unit can deliver during a busy first hour. At a glance, a 40-gallon tank serves 2–3 people with an FHR around 60–70 gallons and costs $1,200–$2,000 installed. A 50-gallon tank serves 3–4 people with an FHR around 70–80 gallons and costs $1,400–$2,500. A 75-gallon tank serves 5-plus people with an FHR near 90–100 gallons and costs $2,500–$4,000.
| Capacity | Best For (people) | Installed Cost | First Hour Rating* |
|---|---|---|---|
| 40 gal | 2–3 | $1,200–$2,000 | ~60–70 gal |
| 50 gal | 3–4 | $1,400–$2,500 | ~70–80 gal |
| 75 gal | 5+ | $2,500–$4,000 | ~90–100 gal |
*Approximate; varies by fuel type and model.
Use household size and peak demand as your guide:
- 40 gallon: 2–3 people, 1–2 bathrooms, lighter simultaneous use
- 50 gallon: 3–4 people, 2–3 bathrooms — the safe, popular default
- 75 gallon: 5-plus people or homes that run showers, laundry, and the dishwasher at once
If two showers ever run at the same time, lean toward the 50-gallon.
Choose the larger tank if you regularly run out of hot water, have a growing family, added a bathroom, or use a large soaking tub. Sacramento's colder winter inlet water also means a tank works a little harder in winter, so sizing up adds a helpful buffer.
The gap between a 40 and 50 gallon unit is smaller than most people expect — usually a couple hundred dollars upfront and only a modest difference in annual energy use, since modern tanks are well insulated. For most families, the extra capacity of a 50-gallon is worth the small cost. Our team confirms the right size during your water heater installation visit.
For the typical Sacramento household of 3–4 people, a 50-gallon tank is the sweet spot — enough capacity for back-to-back showers without overpaying for a size you will not use. Smaller households of 1–3 can save with a 40-gallon, and large or multi-generational homes should consider 75 gallons or a tankless system for endless hot water.
Not sure whether a 40 or 50 gallon tank fits your home? Beaver Brothers Plumbing sizes it right the first time and installs it same day. Already have a unit that is struggling to keep up? We also offer fast water heater replacement.
✔ Licensed & insured · ✔ Same-day service · ✔ Upfront pricing
📞 Contact Beaver Brothers Plumbing for a free estimate.
👉 Call (916) 885-1005 today to find your right water heater size.
Is a 40 or 50 gallon water heater better?
It depends on household size. A 40-gallon tank suits 2–3 people, while a 50-gallon tank is better for 3–4 people and handles back-to-back showers. For most families, the 50-gallon is the safer default.
How many people can a 50 gallon water heater support?
A 50-gallon tank comfortably supports a household of 3–4 people with 2–3 bathrooms, thanks to a First Hour Rating around 70–80 gallons.
Does a 50 gallon use more energy than a 40?
Slightly, but the difference is small. Modern tanks are well insulated, so a 50-gallon uses only modestly more energy per year than a 40-gallon of the same fuel type and efficiency.
How much more does a 50 gallon cost?
Usually only a couple hundred dollars more. A 40-gallon gas tank runs about $1,200–$2,000 installed, while a 50-gallon runs $1,400–$2,500.
Should I upgrade from 40 to 50 gallon?
Upgrade if you often run out of hot water, added a bathroom, or your family has grown. The extra capacity is inexpensive and prevents cold showers during peak use.
