Free web software for construction estimating.

Yes. Every calculator runs in your browser with no account and no usage limit.

Each tool states its own assumptions and constants, with a source, in its "How we calculate this" section — nothing is a hidden black box.

These are early-appraisal planning tools, not a substitute for a surveyed quantity takeoff or a qualified engineer's sign-off. Always verify before using a figure in a bid or for construction.

Yes — every calculator has a metric/imperial switch, and defaults to a pre-filled example quantity schedule you can edit or replace by uploading your own Excel or CSV file.