It is hard to make a judgement for all entirety of the language (one should probably do a search in a large computer dictionary or a large corpus).
However, you can tackle it from the other side: which of the two you are going to encounter more often. According to frequency dictionaries, feminine nouns are the majority of the most used Ь-ending nouns (I am talking not about only the top-500, but a few thousands).
In the frequency list for spoken speech about 60% of all Ь-nouns in the first 1500 most popular words (and even 3000, 5000) are feminine. It covers 62-65% of usage of such nouns (mind, though, that top-5000 list only covers about 85% of all words). Also, 16 out of 22 in the first thousand are feminine. День, рубль, родитель, гость, учитель are your survival list of masculine nouns (especially день, which is as popular as feminine жизнь).
All in all, this type of nouns is not that frequent. There are a little under 200 of Ь-ending nouns in the list of the most frequent 5000 words in spoken speech (using the spoken Russian corpus of ruscorpora.ru). It makes less than 9% of all nouns in the list. You'll make your life easier using these tricks:
feminine
- жь, шь, щь, чь ending— hushes.
- ость (-есть). "ост" is a very popular suffix for abstract nouns (скорость, взаимность, новость, свежесть)
- знь at the end. For example: жизнь, болезнь
- треть (1/3) and четверть(1/4) are feminine, same as other fractions of a whole (половина, пятая, шестая часть и т.д.)
masculine
- тель : a popular suffix for professions and other "doers": учитель (teacher), усилитель (amplifier)
- арь: словарь, Also, all month names are masculine (though, not all of them end in -арь)
If you remove suffixed nouns (учитель, словарь) and month names, common masculine nouns in -Ь go as follows:
день, рубль, гость, путь, парень, огонь, камень, ноль,
уровень, дождь, отель, лагерь, корабль, медведь, господь, корень,
царь, зверь, спектакль, стиль, монастырь, король, шампунь, ноготь,
гвоздь, портфель, кашель, кошель, кисель, контроль, ремень, алкоголь,
конь, руль, лось, гусь, пень, автомобиль, коктейль, гриль, госпиталь,
картофель.
A really comprehensive list that covers what a learner is going to encounter up to their higher-intermediate proficiency level.
P.S. When seeing a 'suffix', think for a few seconds whether it is really a suffix.
- "обитель"(abode) is feminine: no suffix here.
- masculine гость(guest) and feminine кость(bone), obviously, don't
have the -ост- suffix.
If you already have some good experience with
Russian, try the following rule of thumb. If you remove the 'suffix',
and rest does not really look like a stem of any word you ever learnt
— there is a good chance it isn't. Of course, occasionally you
encounter зритель (viewer) or председатель (chairman), which are
based on more advanced vocabulary (зрение 'vision' is not obscure,
but if you fail to spot the resemblance, only archaic зреть/узреть
'to see' may help you)