GamerToolHub · free Minecraft tools
Get a smooth curve every time. Set the span and the rise, add legs to turn it into a bridge, and follow the blueprint block by block.
Open the arch builder →Free. No account. Nothing you build is stored.
Arches are where a lot of builds fall apart. Eyeball the curve and one side ends up steeper than the other, or the top is flat where it should be round. This tool works out the exact curve for your span and rise, then shows you the whole thing layer by layer so both sides come out even.
Works on Java and Bedrock. Runs in your browser on phone, tablet or PC. No login, nothing you make is stored. Also on GamerToolHub: the full shape generator (circles, spheres, domes, spiral staircases, towers, pyramids) and the banner maker. Not affiliated with Mojang or Microsoft.