Arc & Arch Layout Calculator is the precision toolkit every carpenter, joiner, mason, stonemason, builder and DIY enthusiast needs to lay out perfect arches and curves on any job — without complex trigonometry and without ever pulling string from a nail. TWO PROFESSIONAL CALCULATORS IN ONE APP Large Arc Layout Set out a large-radius arc inside any confined space — an opening, a wall, a panel or a curved trim run. Enter the chord width plus either the rise (height) or radius and instantly see: