How we predict English release dates

Publishers usually announce English volumes only a few months ahead. For volumes that haven't been announced yet, we make an estimate from two things we know well.

1. The English release pace

Most series come out in English at a steady pace — every two, three or four months. When the Japanese volume is already out, we extend the series' recent English pace (the median of the last three gaps).

2. The Japanese edition

When the English edition has caught up with Japan, the next English volume can't come out before the Japanese one. In that case we take the Japanese release date and add the series' usual delay between the Japanese and English editions. Japanese release dates — including upcoming ones — come from Rui, a Japanese manga release calendar.

How accurate is it?

We tested the method on past releases: 7,274 volumes from 330 series, predicting each volume using only what was known at the time.

Volumes ahead	Typical error	Within 2 months
Next volume	about 2 weeks	82%
2 volumes ahead	about 2 weeks	77%
4 volumes ahead	about 3 weeks	69%

For series that have caught up with Japan the error is larger (about a month for the next volume). That's why we show predictions by month, not by day. Delays, hiatuses and publisher changes can't be predicted.

Where the data comes from

Announced English release dates and ISBNs come from the volume lists on English Wikipedia, which cite publisher pages. We refresh them every week. Once a publisher announces a date, it replaces our prediction.