How to Check If a Countertop Is Level Before Fitting
Published 14 April 2026
An unlevel kitchen countertop causes problems that compound over time — water pools at one end of the sink, appliances like toasters and coffee machines wobble, cabinet doors misalign, and the worktop joint between sections gaps on one side. All of this is preventable by checking the level of the base cabinets before the countertop goes down.
What you need to check a countertop level
Timber shims or plastic packers, a screwdriver (for adjusting cabinet legs), and your phone with Spirit Level Online open in the browser.
Check the cabinets before the countertop
It's far easier to level the base cabinets before the countertop is fitted than to correct it afterwards. Most kitchen cabinets have adjustable legs underneath — threaded feet that screw in and out. Getting these right is the key step.
Step-by-step: how to level kitchen cabinets before fitting a countertop
Check the floor first. Place your phone flat on the floor where the cabinets will sit and open Spirit Level Online in Surface Mode. If the floor slopes significantly, you'll need to compensate with the cabinet legs rather than assuming the floor is your reference.
Position the first cabinet and check level. Place the first cabinet in position. Lay your phone on the top of the cabinet carcass and check both left-to-right and front-to-back. Adjust the cabinet legs until the reading reaches 0.0° in both directions.
Bring subsequent cabinets to the same height. Position the next cabinet and check that its top is at the same height as the first. Use your phone on a long straight board laid across both cabinets to check they are at the same level. Adjust the legs until the board reads 0.0°.
Check along the full run. Once all cabinets are in position, check the level along the full length of the run — front edge and back edge separately. A long kitchen run can hide a gradual slope that individual cabinet checks don't reveal.
Screw cabinets together and to the wall. Once everything is level, screw adjacent cabinets together and fix them to the wall. Fixing before levelling is a common mistake — it locks in any error.
Final check with the countertop in place. Once the countertop is fitted, place your phone on it and verify. Countertops can introduce their own flex — particularly long stone or solid wood worktops. If the reading has shifted, add shims between the cabinet top and the worktop to correct it before siliconing the joints.
Tip: Check at the sink cutout. The area around a sink cutout is where countertop level matters most — water runs to the lowest point. After fitting, run a small amount of water on the countertop surface and watch where it flows. It should drain toward the sink, not away from it.
Checking an existing countertop
If your existing worktop has developed a slope — common as cabinet legs settle or floors shift — place your phone on the worktop and check the reading. A slope of more than 1° is noticeable in daily use. To correct it, unscrew the worktop from the cabinets, adjust the cabinet legs, and re-fix the top. It's a straightforward job that takes about an hour.
Joining two worktop sections
Where two worktop sections meet at a corner or join, both sections must be at exactly the same height for the joint to sit flush. Check each section individually, then place your phone across the joint on a rigid board to verify they are at the same level before fixing. A mismatch at a joint is both unsightly and a hygiene risk where food debris can collect.
For kitchen fitting, bathroom installations, and all levelling jobs around the home — Spirit Level Online works directly in your browser with no app download required.