Translation guide
The English word "roughly" has two main uses: (1) indicating an approximate number or amount, and (2) describing an action done in a rough, violent, or careless manner. These meanings require different Japanese expressions.
Expressing that a number, amount, time, or quantity is not exact; about, around, approximately.
It costs roughly $50. · Roughly how long will it take? · There were roughly 100 people.
The most standard and neutral way to say "approximately" or "roughly" before a number. Used in both spoken and written Japanese.
約50ドルかかります。
It costs roughly $50.
Describing an action done with force, violence, lack of care, or coarseness; not gently or smoothly.
He handled the box roughly. · Don't treat the equipment roughly. · She pushed him roughly.
Adverbial form of 乱暴 (violent, rough). Means doing something in a rough, violent, or reckless manner. Can also imply rudeness or force.
彼は箱を乱暴に扱った。
He handled the box roughly.
All three mean "approximately," but 約 is the most neutral and can be used in any situation. 大体 is more casual and often used in conversation. およそ is slightly more formal and common in writing or speeches. くらい/ぐらい is a suffix attached directly to numbers and is very colloquial.
乱暴に only means "in a rough/violent manner." It cannot be used to mean "approximately." Using it with numbers would be nonsensical.
ざっと言って、約10キロです。
Roughly speaking, it's about 10 kilometers.
Combines ざっと (rough estimate) with 約 (approximately).
彼は私を乱暴に押しのけた。
He roughly pushed me aside.
約100人が参加しました。
Roughly 100 people participated.
Very common in casual conversation. Means "roughly," "mostly," or "generally." Can also be used as an adverb meaning "for the most part."
大体どのくらいかかりますか。
Roughly how long will it take?
大体の人数を教えてください。
Please tell me the rough number of people.
Similar to 約 but slightly more formal or literary. Often used in written contexts or formal speech.
その建物はおよそ500年前に建てられました。
That building was built roughly 500 years ago.
Implies a quick, rough estimate or a brief overview. Often used with verbs like 見る (to look), 読む (to read), 計算する (to calculate).
ざっと見積もって、費用は100万円くらいです。
Roughly estimating, the cost is about 1 million yen.
資料にざっと目を通しました。
I roughly looked over the materials.
Attached to a number or quantity to mean "about" or "approximately." Very common in spoken Japanese. ぐらい is a more colloquial variant.
10分くらい待ってください。
Please wait roughly 10 minutes.
100人ぐらい来ました。
Roughly 100 people came.
More formal than くらい. Often used in written Japanese or polite speech to mean "about" or "approximately."
1時間ほどお待ちください。
Please wait roughly one hour.
Please don't use the machine roughly.
Adverbial form of 荒々しい (wild, rough, violent). Emphasizes a wild, coarse, or violent manner, often with a nuance of natural force or lack of restraint.
彼は荒々しくドアを閉めた。
He roughly slammed the door.
Adverbial form of 手荒い (rough, violent, harsh). Specifically refers to rough handling or treatment, often involving physical force.
荷物を手荒く扱わないで。
Don't handle the luggage roughly.
Means carelessly, roughly, or sloppily. Implies a lack of proper care or respect, often used when someone does something in a perfunctory or dismissive manner.
彼は書類をぞんざいに机に投げた。
He roughly tossed the documents onto the desk.