Which tool do I need?
Trying to work out what a channel earns — yours or one you're studying? The RPM Calculator. Give it views and the RPM from YouTube Analytics to estimate revenue, or give it real earnings and views to find your RPM and an estimated CPM. It has no table by niche; the one study it cites is named and dated on the page.
Want your engagement as a rate rather than a pile of counts? The Engagement Rate Calculator. It works the rate out by followers and by reach or views, explains why the two differ, and sets each beside the published studies that divide by the same audience, with each study's date, sample and definition.
About to upload a video? Run the packaging through the Thumbnail Checker first. A thumbnail that looks great at full size routinely dies at sidebar and mobile-feed size, and the duration badge usually sits where people put their text. The banner mode does the same job for channel art against YouTube's safe area.
Still writing the video? The Script Timer tells you how long your draft will run at the speaking pace you choose — or, working backwards, how many words fit a target runtime, which is the fastest way to stop a 10-minute idea becoming a 22-minute video.
Repurposing widescreen footage for Shorts, TikTok or Reels? The Aspect Ratio Calculator gives you the exact 9:16, 1:1 and 4:5 crop dimensions from your source resolution, so you're not eyeballing the crop in the editor.
Where these tools quote third-party figures (one study's RPM figures, engagement figures by platform), each is named and dated on its page, because creator-economy numbers drift fast and an undated figure is worse than none. Check the "last verified" line on each tool before leaning on it.