How to use it
Start with your school's written prom dress code. Copy each rule into the first half of the checker. If your code does not mention something, leave it on Not sure. The checker will never guess a rule for you. It will tell you to ask.
Then measure your dress, wearing the shoes you plan to wear. Take a big step when you check the slit, because slits open higher when you walk. Raise your arms for the midriff check, and lean forward for the neckline. Our page on whether your dress will pass explains each test in detail.
Reading your result
Each area comes back as Passes, Does not pass, or Ask your school. Ask means your code does not settle the question, or your dress is right on the line. Those are worth an email to the person named on your dress code, with photos, before you buy or alter anything.
A Does not pass is not the end of the dress. Slits can be stitched lower, open backs and cut-outs can be filled with mesh, and two-piece sets can often be joined. Our guide to fixing a dress that won't pass covers what a tailor can do and how long it takes.
What it cannot tell you
Some schools judge a dress on the person wearing it, and some ask to see the whole outfit before prom. The checker cannot see your dress. Treat a pass as a good sign, not a promise, and keep any written answer from your school. Our guide to prom dress codes explains how schools write and enforce these rules. When you are ready to shop, you can browse prom shops by state and bring your code along.