Which spelling is correct: "benefiting" or "benefitting"?
Solution 1:
Both spellings are considered to be correct; given the pattern of American English to prefer the shorter of alternate spellings (see color vs. colour; aluminum vs. aluminium), I would summarise that in the US the single-t version would be correct.
However, I see that the two-t version appears more often in searches, so it has popularity going for it.
Solution 2:
Both are considered correct in the English language. Benefiting and benefitting both are acceptable due to two different English spelling rules.
If the final syllable is not accented/emphasized and it does not end in an l then you do not double the consonant. If you say ben-e-fit, you accent ben, the first syllable.
I believe it can become benefitting as well, due to the other English rule, that if a word ends with a short vowel followed by a consonant, you double the consonant so the vowel doesn’t become long.
Due to these two rules, I guess it can be spelled both ways.
Solution 3:
Google found 12.900.000 (approximately) matches for benefiting , but only 1.210.000 for benefitting.
References:
Merriam Webster lists both as correct spelling http://www.merriam-webster.com/dictionary/benefitting
http://www.thefreedictionary.com/benefitting