How to Determine Bathroom Fixture Dimensions

Designing a bathroom is an involved process, from choosing tiles to picking out paint colors to figuring out bathroom fixture dimensions. You’ll want your fixtures to coordinate throughout the space and to fit into their designated slots as well. There are typical dimensions for tubs, sinks and cabinets. As you design your bathroom layout, it’s nice to have a general idea of what they are. However, knowing how to measure out your bathroom fixtures is an asset as well. 

Step 1 – Know Basic Builder’s Fixtures Measurements 

Builder’s fixtures have typical measurements you can rely on. They are as follows:

1. Standard tub – 30 inches wide, 60 inches long and often 15 inches deep (but you can upgrade to varying depths, such as a 36 inch deep soaking tub)
2. Standard toilets – round: 24 inches by 19.5 inches by 26 inches and elongated: 30.5 inches by 19.5 inches by 26 inches 
3. Basic Cabinets - modular sink base: 24 inches to 36 inches wide; drawer sink base: 12 inches to 18 inches wide; and standard vanity base: 12 inches to 18 inches wide

Step 2 – Know Correct Layout Codes 

Check with your local building department to discover what codes are in place in relation to bathroom layout. Make sure all the fixtures have enough clearance around them. For the bathroom cabinet, plan about 30 inches clearance (or more) so that you can open the doors and bend down in front of it. Building codes often call for no less than 20 inches clearance in front of the toilet bowl. All around it, plan for 18 inches to the closest wall or 14 inches to the closest cabinet, measuring from the center of your bowl. 

Step 3 – Measure Existing Fixtures 

Write the measurements of your current bathroom fixtures in a notebook. Make sure you measure everything with extreme care. To give an example, when measuring a sink that goes into a cabinet, be certain to get the length, width and depth of your fixture. 

Step 4 – Measuring Oddly Shaped Fixtures 

If you have an oddly shaped fixture, use a pencil and tracing paper to draw an outline of the unit. That way, you’ll be able to take your drawing to the store when you’re choosing another sink. For something like an odd shower faucet, consider drawing a diagram that you can take with you when you are purchasing replacement fixtures. Take several measurements when drawing the diagram. It’s never undesirable to be thorough. 

Step 5 – Think About Size 

Though it might seem that you are bound to buying replacement fixtures that are the same size as your current fixtures, that’s not necessarily the case. You can alter drywall, ceramic or wood materials that might be blocking a new, larger fixture from fitting into place. A smaller fixture than your existing unit, however, might leave a very noticeable gap in flooring or wall material.