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Mount a grab bar 33 to 36 inches above the floor and anchor it into framing or solid blocking, not tile and drywall. Plan two bars at the toilet (one behind, one beside) and up to four around a tub: two on the back wall, one on the control end wall at the tub entry, and one on the head end wall. Those numbers come from the ADA standards for public buildings. A private home is not bound by them, but they are the most detailed public specification there is, so installers and owners use them as a benchmark.
CDC's falls guidance says to put grab bars inside and outside the tub or shower and next to the toilet (CDC, preventing falls). The ADA text supplies the positions.
A grab bar is 1-1/4 to 2 inches thick and survives 250 pounds
Section 609 of the ADA 2010 Standards sets the bar: 1-1/4 to 2 inches in diameter, a 1-1/2 inch gap between bar and wall, mounted 33 to 36 inches above the floor, and strong enough to take 250 pounds of force at any point (ADA 2010 Standards). A towel bar is not built to that load.
Toilet: one bar behind, one beside
Section 604.5 calls for two bars at the toilet.
| Bar | Minimum length | Position |
|---|---|---|
| Side wall (nearest the toilet) | 42 in | No more than 12 in from the rear wall; reaches at least 54 in from the rear wall |
| Rear wall | 36 in | At least 12 in on one side of the toilet centerline and 24 in on the other |
If a recessed fixture limits the rear wall, the standard allows a 24 inch bar centered on the toilet. If the flush control is in the way, the rear bar may be split or shifted to the open side.
Tub: a horizontal bar, a second bar and one at the entry
Section 607.4 depends on whether the tub has a permanent seat. For a tub without one, the back wall carries two bars. One sits at the standard 33 to 36 inch height, and the other 8 to 10 inches above the rim of the tub. Each is at least 24 inches long, no more than 24 inches from the head end wall and no more than 12 inches from the control end. The control end wall gets a bar at least 24 inches long at the front edge of the tub, and the head end wall a bar at least 12 inches long, also at the front edge.
With a permanent seat the back wall limits change (no more than 15 inches from the head end) and the head end bar is dropped.
Shower: matching heights, bars near the corners
Section 608.3 says horizontal bars in a shower should be at the same height above the floor. For roll-in showers the bars sit no more than 6 inches from the adjacent wall, on the back wall and the side wall opposite any seat, with none above the seat. A shower without a seat gets bars on three walls. Most home showers are not roll-in, so treat this as a guide.
The wall has to carry the load
The 250 pound figure applies to the bar, its fittings and the wall behind it, so the load has to reach framing or blocking, which is a board fitted between studs. The ADA text gives the force but not the blocking dimensions, and no primary source opened for this page does either. Follow the bar maker's installation sheet and ask the installer where the blocking will go.
If the wall is open, as in a remodel or a gutted bathroom, blocking can go in before the new wall surface so bars can be placed exactly where you want them later. If the wall is closed, a stud finder shows where the framing is, and the bar position may need to move to meet it.
For cost, Fixr's aging-in-place guide gives $90 to $300 for grab bar installation (Fixr, last updated August 2022). It is a secondary guide, not a quote, and the figure predates current labor prices, so get a local quote.
Suction bars are not grab bars
A suction bar sticks to a smooth surface and can be moved. CARP, a Canadian seniors' organization, says these bars "are not designed to hold your weight," that most are labeled for balance or stability only, and that they "can loosen without warning" (CARP, April 2026). CARP is an advocacy source, not a testing body, so read the label on the one you own. Do not lean on a suction bar to catch a fall or to steady yourself getting in or out of the tub. Only a bar fixed into framing or blocking is a grab bar.
Test the positions with your own hands before you drill
Sit on the toilet and stand up. Step into the tub as you would at 2 a.m. Mark where a hand goes, then compare it with the tables above and adjust to the person's height and reach. For medical questions about balance or falls, talk to a doctor.