Is that lead big enough? Enter the count so far and how much is left, then see what the trailing candidate needs from the uncounted vote.
If you know a chunk of the uncounted vote will break differently (late mail, a county, provisionals), add it here with its own split.
How far off could the “% counted” estimate be? The break-even range and the grey band on the meter use this. Most people can leave it at ± 3.