How do I choose a toilet for my home?

### What do I measure before I shop?

MaP's buyer checklist starts with these:

• Rough-in. This is the distance from the wall behind the toilet to the center of the floor bolts. MaP says most North American homes are 10, 12 or 14 inches, and 12 is the most common today. Measure to the bolts, not the base edge.
• Footprint. A new toilet with a smaller base can leave bare floor or a gap in the tile where the old one sat.
• Wall behind the tank. A smaller new tank can expose unpainted wall.
• Shelf above the toilet. If a shelf hangs over the tank, leave room to lift the tank lid and reach the parts inside.
• Shut-off valve. Check the valve on the wall that feeds the toilet. If it's stuck or weeping, MaP notes replacing it may be a job for a plumber.

Clearances around the toilet are a code question too. Our page on how much space a toilet needs has the numbers.

### Round front or elongated?

Round-front bowls are smaller, so MaP calls them ideal for compact bathrooms. Elongated bowls run as much as 2 inches longer and are considered more comfortable for adults and better for hygiene. The catch is space: MaP warns of cases where doors and drawers wouldn't open after an elongated bowl replaced a round one. Check the swing before you commit.

### What bowl height should I get?

Conventional bowls sit about 14 to 15 inches off the floor at the rim, and comfort-height (chair-height) bowls about 16 to 18 inches, per MaP. Those numbers leave out the seat. The ADA Standards for accessible toilets set the seat at 17 to 19 inches above the floor, measured to the top of the seat, and for residential dwelling units they allow 15 to 19 inches. A taller bowl is easier on knees and backs, while a standard height suits small kids. Comfort height versus standard height goes through who should pick which.

### One-piece, two-piece or skirted?

MaP says two-piece toilets are the most common, usually cost less and have a taller tank. One-piece toilets generally cost more but are often easier to clean and look sleeker. A skirted base hides the trapway, which mostly helps with cleaning and doesn't change the flush. See what a skirted toilet is and whether it's easier to clean. Wall-mounted toilets hang from a carrier inside the wall, so they're a remodel decision, not a swap.

### Smaller details that still matter

MaP also lists the flush handle position (right side, right front, left side, left front or top-center of the lid), color, and tank insulation. On color, MaP recommends white or off-white, since a trendy color can force you to replace the sink and tub to match, and can hurt at resale. Handle position is a small detail you'll notice every day.

### Why choose a WaterSense toilet?

EPA says WaterSense toilets use 1.28 gallons per flush or less, which is 20 percent less than the current federal standard of 1.6, and are independently certified for both efficiency and performance. EPA also says replacing old toilets with WaterSense models can cut toilet water use by 20 to 60 percent for the average family. If you're not sure what your current toilet uses, look for the gallons-per-flush marking, which the City of Phoenix says is typically inside the tank.

### How do I judge flush performance?

Look up the MaP score. It's the grams of solid waste (soybean paste and toilet paper) a model can flush completely in a single flush, and MaP says its testing is independent and voluntary. WaterSense requires a toilet to clear 350 grams of test media and four balls of toilet paper in four of five flushes, and EPA says those waste-extraction requirements have since been adopted into the national standard, so every toilet sold in the U.S. or Canada must meet them. MaP says scores of 500 and above give excellent performance. It also says price doesn't predict flush quality: some of the best performers are among the least expensive.

### Gravity, pressure-assist or vacuum-assist?

Gravity-fed is the common type and relies on the weight of tank water. Pressure-assist uses line pressure to compress air in a vessel inside the tank for a stronger flush. MaP says pressure-assist toilets don't sweat in humid climates, but they can cost more, be harder to repair and be louder. Vacuum-assist uses a mild vacuum to help pull the flush. For most homes, a high-scoring gravity model is the right call. MaP also notes that most water-efficient models don't empty the tank on each flush, so condensation is less of a problem than it was with older toilets.

### How does hard water affect a toilet?

It's a reason to plan for upkeep. The City of Phoenix's 2025 water quality report lists total hardness of 172 to 302 ppm (10 to 17.6 grains per gallon) and says hardness can cause scaling on plumbing fixtures. Kohler says hard water deposits can restrict flow through the rim holes and cause poor rim wash, and its fix is to ream the holes and soak them with a hard water deposit or lime-dissolving cleaner. So no toilet is immune here. Plan to check the rim holes if the bowl stops rinsing well, and see how hard water damages plumbing for the wider picture.

### Is there a Phoenix incentive?

The City of Phoenix runs an incentive for buying and installing a WaterSense toilet of 1.28 gallons per flush or less. Its terms include a limit of two toilets per home within 10 years and a requirement that the old toilet use at least 3 gallons per flush, and it asks for a receipt, photos and the make and model, so read the current rules and amount before you buy. The city says residents can expect each new toilet and irrigation controller to save approximately 10,000 gallons per year.

Use this table as a last check before you buy.

Buying is your call, but a plumber earns their keep on the swap itself when the old flange is cracked, the floor is soft, or the shut-off valve won't close. HQ Plumbing & Air is licensed and insured and gives free estimates, and we quote the price upfront before we start. For what goes into the total, see what drives the cost to replace a toilet.