に関わらず【にかかわらず】

に関わらず means "regardless of": the outcome stays the same whatever value the factor takes. It follows a noun that names something which varies – age, the weather, the result – or a pair of opposites, and it is also written in kana, にかかわらず.

The noun has to be a range, not one value of it. "Rain" is one kind of weather, so it cannot be ignored "regardless": ×雨に関わらず, but てんき天気にかかわら関わらず or あめ雨でも.

Pairs of opposites

"Whether X or Y" is a pair, each half ending in か. For a verb, the pair is the dictionary form and the ない-form, or a clause with かどうか. Paired kanji like うむ有無 "having or not", だいしょう大小 "big or small" and すききらい好き嫌い pack a pair into one noun.

に関わらず or にもかかわらず

One も makes the opposite point. に関わらず says the factor does not matter. にもかかわらず means "despite": the factor should have mattered, and the result went against it.

Register

に関わらず belongs to notices, rules and formal speech. をとわ問わず means the same and is just as formal; it suits categories such as せいべつ性別をとわ問わず, "regardless of gender". In conversation, say かんけいなく関係なく.