ごとに

ごとに means "every" or "each". After a time word or a number with a counter it gives a regular interval; after an ordinary noun it says something applies to each one separately. It follows the noun directly.

ごとに or おきに

With minutes, hours or metres the two mean the same: ごふん５分おきに is every five minutes. With days, years or counted things, おきに counts the gap between, so it skips one more than ごとに.

Usage notes

These go beyond a fixed interval or each item in turn.

Every time something happens

After a verb in the dictionary form, ごとに means "every time". The second half usually describes something that builds up.

Day by day

ひごとに日ごとに and ねんごとに年ごとに also describe a change that grows as time passes: "day by day", "year by year".

ごとに can be written ごとに毎に, but the hiragana spelling is the usual one.