How to Measure and Install a New Toilet (Step-by-Step Guide)

Installing a new toilet is a straightforward process if you have the right measurements and tools. Whether you're upgrading an old toilet or installing one in a new space, this step-by-step guide will help you get the job done correctly and efficiently.

Step 1: Gather Your Tools and Materials

Before you start, make sure you have:

Step 2: Measure for the Right Fit

To ensure your new toilet fits properly, take these measurements:

  1. Rough-In Distance: Measure from the wall (not the baseboard) to the center of the closet flange (the hole in the floor where the toilet connects). Standard rough-in sizes are 10, 12, or 14 inches.
  2. Bowl Shape: Choose between round (better for small spaces) and elongated (more comfortable) toilet bowls.
  3. Clearance Space: Measure side-to-side and in front of the toilet to ensure it meets local building codes and provides comfortable use.

Step 3: Remove the Old Toilet

  1. Turn Off the Water Supply – Locate the shutoff valve behind or beside the toilet and turn it off.
  2. Drain the Toilet – Flush to remove water, then use a sponge and bucket to soak up any remaining water.
  3. Disconnect the Supply Line – Use an adjustable wrench to unscrew the water supply hose.
  4. Remove the Bolts – Unscrew the bolts at the toilet base. If they are rusted, cut them off with a hacksaw.
  5. Lift the Toilet and Remove the Wax Ring – Gently rock the toilet to break the seal, then lift and set it aside. Scrape off the old wax ring and clean the flange.

Step 4: Install the New Toilet

  1. Install a New Wax Ring – Place a new wax ring or rubber seal on the closet flange.
  2. Position the Toilet Bowl – Lower the toilet straight down onto the wax ring, aligning the mounting holes with the floor bolts.
  3. Secure the Toilet – Press down gently to set the seal, then tighten the nuts onto the bolts evenly to avoid cracks. Do not over tighten.
  4. Attach the Tank – If your toilet has a separate tank, secure it using the included bolts and washers.
  5. Reconnect the Water Supply – Attach the supply hose and turn the valve back on.
  6. Check for Leaks – Flush the toilet a few times and inspect for any leaks around the base or supply line.
  7. Seal the Base (Optional) – Apply a bead of silicone caulk around the base for a finished look and added stability.

Measuring and installing a new toilet is a manageable DIY project with the right tools and steps. By following this guide, you can ensure a proper fit, secure installation, and long-lasting performance. If you encounter issues like leaks or an uneven toilet, double-check your seals and leveling, or consult a professional plumber for assistance.