ArchiCalc

ArchiCalc is a dimensional calculator for architects and builders. It is designed to make working with imperial and metric dimensions fluid and easy. Designed by an architect for architects, ArchiCalc works in a natural intuitive way with numbers, lengths, areas and volumes. Metric and Imperial units can be added together without converting in advance and can be freely converted to units of your choice. ArchiCalc understands that lengths multiplied by lengths result in areas. Areas multiplied by lengths result in volumes.
Archicalc supports standard calculator functions as well as specialized geometric operations for triangles, circles and spheres. Lengths can be freely converted between foot-inch/ fraction notation, decimal feet, fractional inches, decimal inches, yards, meters, centimeters and millimeters. Area units supported include acres, ft², in², yd², m², cm² and mm². Volumes units include gal, ltr, ft³, in³, yd³, m³,cm³ and mm³.
Memory is provided for ten values. An on screen Tutorial introduces the basics and help is available for every key.