Yes. All calculators are free, require no login, and have no usage limits. Use them as many times as you need for any project.

Accurate enough to order from, once you confirm the final count with your supplier. I build in the standard industry waste factors and rounding conventions, because every real job loses material to offcuts and mistakes, and an estimate that ignores that sends you back to the store mid-project. Treat the result as a solid planning…

Yes. Every calculator works on your phone in any modern browser, with nothing to install. I built them to be used on the job site, not just at a desk.

No, and that is deliberate. Nothing you type leaves your browser, so there is nothing to store or transmit and nothing for me to see. If you want the figures later, screenshot or note the output before you close the tab.

Tell me through the contact form and I will look at adding it. I build the calculators readers ask for, so when the formula is standard and the use case is practical, it usually lands in a future update.