Accurate, Precise, Exact
noun, な adjective
It is correct and you're certain of it. When you've done this much checking and you're this sure, your measurements must be very accurate and precise.
せいかく
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
コンピュータで計算したので、正確ですよ。
I did the calculations on the computer, so they are accurate.
その記者の報道はいつもとても正確です。
That reporter's reporting is always very accurate.
コウイチはワニカニの正確なユーザー数を知りません。
Koichi doesn't know the accurate number of WaniKani users.