FAQ
Answers to common questions about using Zayvora Calculators.
Using the calculators
How do I use a calculator?
Pick a calculator, type your numbers and press Calculate or Enter. Rates and defaults are editable boxes. Every page explains its formula and shows a worked example, so you can check any result by hand.
Are the calculators free, and do I need an account?
They are free. There is no sign-up, no download and no account.
Can I change the default rates and prices?
Yes. Fee rates, prices, sun hours and similar values are boxes you can edit. The starting values are placeholders, so replace them with the numbers from your own account, bill or quote.
Do the calculators work on a phone?
Yes. The pages and tools are built to work on phones and tablets as well as on computers.
Accuracy and rates
How accurate are the results?
Results are estimates worked out from the formulas and the numbers you enter. Display rounding is applied only at the end. Real costs also depend on things a simple tool cannot see, such as category, account type, shade, ground conditions or local rules.
Why does my result differ from another site or my statement?
Sites make different assumptions about fees, tax, categories and rounding. Compare the inputs first, then check the official source for your account.
Where do the default rates come from?
The eBay and Etsy defaults are US rates as published on their fee pages in October 2026. Other defaults, such as cost per watt, electricity price or filament price, are placeholders for you to replace.
Do the calculators give financial, tax or professional advice?
No. They give estimates for information only. Please read the Disclaimer and ask a qualified professional before making a decision.
Privacy
Do you store or send the numbers I type?
No. Every calculation runs in your browser. Your inputs are not sent to our server or stored, and they disappear when you close the page.
Does the site use advertising or analytics?
Not at the moment. If that changes, the Privacy Policy will be updated before it happens.
About the site
How do I report a mistake or suggest a calculator?
Use the Contact form and choose “Report an error” or “Suggestion”. Tell us which calculator you used and what you entered. Confirmed errors are fixed and the “Last updated” date of the page is changed.
Who runs Zayvora Calculators?
It is an independent project by Ubaid Ullah, a digital marketer and SEO specialist. See the About page for how the tools are built and checked.
Last updated: October 2026