Terms
Mostly one point: these are published prices read from award charts, not live seat availability, and points transfers cannot be undone.
What this site is
A calculator over published airline award charts. Every figure carries a link to where it was read and the date it was read on, and where a number could not be confirmed the page says so rather than filling the gap.
What it does not know
Whether a seat is actually available. Award charts state a price; they say nothing about whether the flight you want has a reward seat on the date you want it. A price here means the fare exists, not that you can book it.
Airlines change charts, transfer ratios and surcharges without notice, and several in this list have done so mid-year. A figure read three weeks ago may be wrong today, which is why every one shows its date.
Before you transfer
A transfer of points to an airline cannot be reversed. Confirm the price with the airline itself, and confirm a seat is available, before moving anything. If this site and the airline disagree, the airline is right.
Not advice
Nothing here is financial advice, and no part of it recommends a card, a product or a purchase. It does not tell you what a point is worth, because that depends on what you would otherwise have paid, which only you know.
Mistakes
There will be some. The figures are transcribed from published documents by hand and by machine, and both make errors. Several have already been found and fixed, and the working assumption is that more remain. Use the source link beside any figure you are about to act on.
Your balances
What you enter is yours. It is stored so the site can answer questions about it, it is not shared, and you can remove it. See the privacy page.