What Is ばか (Baka) in Japanese? How Is It Used?

ばか means idiot, ridiculous, silly, foolish, stupid, or ignorant.

It can be written in hiragana, ばか (baka), in katakana, バカ (baka), or kanji, 馬鹿 (baka). 馬 means “horse,” and 鹿 means “deer.” You must be asking yourself, “Why in the world would a horse and deer be considered stupid?” These characters are known as 当て字 (ateji). These are kanji characters used in words solely for their reading without considering their meaning (or vice-versa).  

It is often written in katakana when the “ba” part is extended to show stronger emotion (like anger) or when being playful: バーカ (bāka

Originally, this word included feelings of contempt and was insulting. Nowadays, it can also be used in a lighthearted or even affectionate way with people you are close to. 

While ばか (baka) can be used playfully, how you say it can mean the difference between friendly banter and a direct insult. You’ll also need to consider your situation; you would never use ばか in any formal or polite setting.  

How to Use ばか (Baka) Naturally in Japanese?

Here are the main ways ばか (baka) is used by native Japanese speakers.

1. Using ばか (Baka) Playfully / As a Joke

When you are with people you have a close relationship with (like your friends), you can use ばか (baka) as a way to tease or joke around with them playfully. While calling someone an “idiot” sounds harsh in English, it is not so bad in Japanese (if said playfully). Its nuance is closer to calling someone a “clutz,” “spaz,” or “crazy” in English.  


1. 今朝、健がバナナの皮で滑って転んだのを見たよ!馬鹿だよなー!
(Kesa Ken ga banana no kawa de subette koronda no o mitayo! Baka da yo na!)
I saw Ken trip over a banana peel this morning! He is such a clutz!

2. 今朝は寝ぼけていて、歯磨き粉で顔を洗っちゃったのよ。私って本当に馬鹿だわ!
(Kesa wa neboketeite hamigakiko de kao o aracchatta no yo. Watashitte hontō ni baka dawa!)
I was half asleep this morning, so I washed my face with toothpaste.  Silly me!

3. Tシャツを反対に着ているよ!バーカだね!
(T shatsu o hantai ni kiteiru yo! Bāka da ne!)
Your T-shirt is on backward! You spaz!

 2. Using ばか (Baka) As An Insult (Fighting Words)

Saying ばか (baka) angrily or in an insulting way is…well, insulting. Variations on ばか, such as 馬鹿野郎 (bakayarō) or 馬鹿たれ (bakatare), can also be used to insult someone. Both 馬鹿野郎 (bakayarō) and 馬鹿たれ (bakatare) mean moron or bastard and are rougher than ばか (baka). They are only used to convey hostile (harmful or insulting) meanings.  

馬鹿野郎 (bakayarō) is the roughest-sounding expression and is only used when you purposely want to be insulting.  


1.  馬鹿野郎!自分の名前さえもきちんと書けないのか!
(Bakayarō! Jibun no namae sae mo kichinto kakenai no ka!) 
You moron! Can’t you even write your name correctly?

2. 馬鹿野郎!仕事に遅刻するなんてお前はクズだ!
(Bakayarō! Shigoto ni chikoku suru nante omae wa kuzu da!)
Hey a*hole! You’re a piece of sh*t for being late to work!   

Using ばか (Baka) to Express Reassurance

When someone says something out of misguided fear or a lack of self-confidence, you can use ばか to tell them their thinking is wrong in an affectionate way. For example, imagine someone saying they are not pretty (even though they are). You can tell them that’s ばか to mean “that’s ridiculous” or “that’s silly” in English.  


Hanako: (Otōsan taihen! Suika no tane o nomikonjatta! Onaka no naka kara suika no me ga haetekichattara dō shiyō!)
Hanako: Dad! I swallowed a watermelon seed! What should I do if a watermelon sprout grows from my stomach? 

Otōsan: (Baka da nā. Shinpai shinaide daijōbu dakara, mō nakanaide.) 
Dad: Silly girl. You’ll be fine, so don’t worry about it. You don’t have to cry.  

In this sentence, バカ (baka) doesn’t mean idiot or stupid. The father is using ばか to reassure his daughter that what she is thinking about is no big deal and she shouldn’t worry about it.  

Using ばか (Baka) As An Interjection 

We often use interjections in English to bring emotion into our sentences. Words like “hey,” “ahh,” or “wow” are just a few examples commonly used in English. ばか is sometimes used in a similar way.  


A girl’s older brother took her toy and hit her while they were playing. Their mother sees this and says: 

(Baka! Nani yatteruno!) 
Hey! What are you doing?!

In this sentence, 馬鹿 doesn’t mean stupid. It is used in a way similar to an interjection, like saying, “hey!”

What Is 馬鹿にする (Baka Ni Suru)?

馬鹿にする (baka ni suru) means to “make fun of someone.”  

Let’s go straight into some examples to see how to use this phrase in Japanese.


1. 健は僕が走るのが遅いからっていつもバカにするんだ。
(Ken wa boku ga hashiru no ga osoi kara tte itsumo baka ni surun da.)
Ken always makes fun of me because I can’t run fast.

2. お兄ちゃんは私が自分の名前を書けないからってバカにするんだよ。
(Onīchan wa watashi ga jibun no namae o kakenai kara tte baka ni surun da yo.)
My older brother makes fun of me because I can’t write my name.

3. 友達が私のことをチビってバカにするんだよ。
(Tomodachi ga watashi no koto o chibi tte baka ni surun da yo.)
My friends make fun of me because I’m short.

How to React To Someone Making Fun Of You Using 馬鹿にする (Baka Ni Suru)

We can use the negative (naide) form of する (suru – to do) to tell people to “stop making fun of me.” There is a male and female version of this phrase.  

Stop Making Fun of Me!

  • Female: 馬鹿にしないでよ!(Baka ni shinaide yo!)
  • Male: 馬鹿にするなよ!(Baka ni suruna yo!)


1. 隆史:また日本語のテストで0点を取ったの?馬鹿だな!
Takashi: (Mata nihongo no tesuto de reiten totta no? Baka da na!)
Takashi: Did you get 0 points on your Japanese test again? You idiot!

Hanako: (Baka ni shinaide yo! Tsugi wa zettai ni makenai kara!)
Don’t make fun of me! I won’t lose next time, for sure!

2. 花子:また遅刻したの?馬鹿ね!
Hanako: (Mata chikoku shita no?  Baka ne!)
Are you late again? You idiot!

    隆史: 馬鹿にするなよ!もう二度と遅刻しないからな!
Takashi: (Baka ni suru na yo! Mō nido to chikoku shinai kara na!)
Don’t make fun of me! I will never be late again!

When to NEVER Use 馬鹿 (Baka)

While 馬鹿 (baka) can be used playfully, it should never be used with someone older than you, who has a higher social status (your boss, teacher, etc.), and in formal situations.  

Words Using ばか (Baka)

Here are some words and expressions that use the word ばか in them. 

 1. 馬鹿らしい (Bakarashii) / 馬鹿馬鹿しい (Bakabakashii): Useless, Silly, Nonsense, Ridiculous

馬鹿らしい (baka rashii) and 馬鹿馬鹿しい (bakabakashii) are both i-adjectives and have almost the same meaning. However, 馬鹿馬鹿しい (bakabakashii) is a more emphatic way of saying something is ridiculous.  


1. 健: 教科書を枕の下に置いて寝ると、テストで満点が取れるんだって! 
Ken: (Kyōkyasho o makura no shita ni oite neru to tesuto de manten ga torerun datte!)
I heard I can get a perfect score on the test if I put my textbook under my pillow when I sleep!

お母さん:馬鹿らしい!/ 馬鹿馬鹿しい ! そんなこと言ってないで勉強しなさい!
Mom: (Bakarashii! / Bakabakashii! Sonna koto ittenaide benkyō shinasai!)
That’s ridiculous!  Don’t say silly stuff like that and get to studying!

2. 健史: この会社に投資すれば絶対に儲かるらしい!
Takeshi: (Kono kaisha ni tōshi sureba zettai ni mōkaru rashii!)
I heard that if you invest in this company, you can make a lot of money!

     智子: 馬鹿らしい!(馬鹿馬鹿しい) ! そんなの詐欺に決まってるでしょ!
Tomoko🙁Bakarashii! / Bakabakashii! Sonna no sagi ni kimatteru desho!)
That’s dumb!  It’s definitely a scam!

3. 健: この壺を買えば願いが叶うらしいよ。
Ken: (Kono tsubo o kaeba negai ga kanau rashii yo.)
I heard that if you buy this pot, it will make our dream come true!

    花子:  馬鹿らしい!/ 馬鹿馬鹿しい! まさかそれを買わないよね?
Hanako: (Bakarashii! / Bakabakashii!  Masaka sore o kawanai yo ne?)
Don’t be silly!  No way! You’re not going to buy it, are you?

2. ばかを見る (Baka O Miru): It Doesn’t Pay to ~. / Feel Like a Fool

1. 正直者が馬鹿を見る。(Proverb)
(Shōjikimono ga baka o miru.)
It doesn’t pay to be honest.  

2. 道で困っている人を助けてあげたのに、文句を言われるなんて、馬鹿を見たよ。
(Michide komatteiru hito o tasukete ageta noni monku o iwarerunante baka o mita yo.)
I helped someone in trouble on the street, but they complained about it. I feel like a fool for helping them.  

3. ばか (Baka) With Nouns / Adjective: Extremely, Terribly, Too Much 

Combining ばか with certain nouns and adjectives can give it a meaning of “too much” or “extremely.”  

1. ばかに暑い (Baka Ni Atsui): Extremely Hot

ばか is both a noun and a na-adjective. To use a na-adjective as an adverb, you use the particle に (ni) after it. ばかに (baka ni) is the adverb form and means “extremely” or “ridiculously.”


(Ondanka no eikyō de kotoshi no natsu wa baka ni atsui.)
Due to global warming, it’s extremely hot this summer.

2. 馬鹿力(Baka Jikara): Extremely Strong

This expression is pretty self-explanitory. Check out these examples to get a feel of how it’s used in natural Japanese.


 1. 健: たかしは一人で家具を全部運び出して引っ越しをしたんだって!
Ken: (Takashi wa hitori de kagu o zenbu hakobidashite hikkoshi o shitan datte!)
I heard Takashi carried all the furniture in his house and moved by himself!

Taro: (Kare wa baka jikara ga aru kara ne.)
Yea, that guy is extremely strong.

2. 花子: 80歳のおじいちゃんが、火事の時に一人で冷蔵庫を家から運び出したんだって!信じられないよね!
Hanako: (Hachijussai no ojīchan ga kaji no toki ni hitori de reizōko o ie kara hakobidashitan datte! Shinjirarenai yo ne!)
When a fire broke out, I heard that an 80-year-old man carried his refrigerator out of his house by himself. It’s unbelievable, isn’t it?  

Takashi:(Kajiba no baka jikara dane!)
People can have ridiculous strength during emergencies (fire). 

*Note:  火事場の馬鹿力 (Kajiba no baka jikara) is a proverb. It means someone who gains incredible power in an emergency like a fire.  

3. バカ高い (Baka Takai): Crazy Expensive

You may be wondering why there is no particle に (ni) after the ばか to change it into an adverb. バカ高い (baka takai) is actually a word on its own. It is an i-adjective that means “Ridiculously expensive.”


花子: 先月まで300円だったパンが今月は500円に値上がりしたんだよ!
Hanako: (Sengetsu made san byaku en datta pan ga kongetsu wa go hyaku en ni neagari shitan da yo!)
Until last month, bread was 300 yen, but the price increased to 500 yen this month!

道子: バカ高いね!
Michiko: (Baka takai ne!)
That’s crazy expensive!

4. バカ騒ぎをする (Baka Sawagi O Suru): Horseplay / To Fool Around

バカ騒ぎ (baka sawagi) is a noun that means “horseplay.” You can add する (suru) to turn it into a verb.  


(Kodomotachi ga ichinichijyū baka sawagi shiteita kara mō kutakuta da yo.)
The kids were horsing around the whole day, so I’m exhausted.

5. 馬鹿にならない (Baka Ni Naranai): Cannot Be Taken Lightly

Let’s jump straight into some examples using this expression.


1. バス代がわずか200円だとしても、毎日バスで通学していたら、バス代は馬鹿にならない。 
(Basudai ga wazuka ni hyaku en da toshitemo mainichi basu de tsūgaku shiteitara basudai wa baka ni naranai.)
Even if the bus fare is only 200 yen, taking the bus every day will add up. It cannot be taken lightly.

2. ポテトチップスを少ししか食べていないと言っても、毎日食べていたら、カロリーは馬鹿にならない
(Poteto chippusu o sukoshi shika tabeteinai to ittemo mainichi tabeteitara karorī wa baka ni naranai.)
You say that you only eat a little bit of chips, but if you eat them every day, you’ll consume a lot of calories.  You shouldn’t take it lightly.

あほ (Aho) Vs ばか (Baka)

あほ (aho) also means “stupid,” “idiot,” or “fool” in Japanese.  The biggest difference is that あほ (aho) is mainly used in Kansai-ben (Kansai dialect) in western Japan. 

For people in Kansai, あほ (aho) can be used as an insult or playfully. However, ばか (baka) is usually taken as a serious insult, so it is better not to use the wordばか (baka) in Kansai. In eastern parts of Japan (think Tokyo), it’s the opposite (あほ is more insulting while ばか is not as strong).  

What is 間抜け (Manuke)?

間抜け (manuke) has a similar meaning to ばか (baka): stupid, foolish, idiot. 間抜け (manuke) is often used to describe people who often make unintentional mistakes.  

Manuke is written in:

  • hiragana: まぬけ
  • katakana: マヌケ
  • kanji: 間抜け


花子: すみません。間違えて違うものを買ってしてしまいました。
Hanako: (Sumimasen. Machigaete chigau mono o katte shimaimashita.)
I’m sorry. I accidentally bought the wrong thing.  

Jōshi: (Mata ka! Kono manuke ga!)
Again! You are such a dimwit!     

Interesting Expressions Using バカ (Baka) 

Here are some expressions using baka that you may encounter when listening to native Japanese speakers.

親バカ (Okyabaka): Parents Who Love Their Children Deepy (Or Too Much)

People often use this word to talk about themselves or people they are close to. Using this word to describe people you are not close to can be offensive.  

A similar word is バカ親 (baka oya), which means, “(Stupid) parent(s) who spoil their children.”


A father is looking at his 2-year-old son, drawing a picture.

1. 夫: 見て!健が絵を描いてるよ!なんて素晴らしい絵なんだ!きっと将来は画家になるぞ!
Otto: (Mite! Ken ga e o kaiteru yo! Nante subarashii e nanda! Kitto shōrai wa gaka ni naru zo!)
Look! Ken is drawing a picture! What a beautiful picture! He’ll be an artist in the future!

    妻: もう本当にあなたって親バカね!
Tsuma: (Mō hontō ni anata tte oyabaka ne!)
You love your son too much!   

2. 花子:あなたの息子がうちの娘を蹴ったせいで怪我したわ!
Hanako: (Anata no musuko ga uchi no musume o ketta sei de kega shita wa!)
My daughter is injured because your son kicked her.

    道子: 何言ってるの!うちの息子はとてもいい子なんだからそんなことするはずがないわ!
Michiko: (Nani itteru no! Uchi no musuko wa totemo ii ko nan dakara sonna koto suru hazu ga nai wa!)
What are you talking about? My son is such a good boy. He would never do such a thing!

    花子: なんてバカ親なの。(Said under her breath)  
Hanako: (Nante baka oya na no.)
What a crazy mother.

Photo of author

Yumi Nakata

Yumi is a native speaker of Japanese. She is living in Kanagawa, Japan, raising her three kids. She studied English as an exchange student in Washington state for a year. The days she spent with her American friends are some of the greatest memories of her life.

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