Correct

不自量

/ bùzìliàng / 
Strokes

Definition

not take a proper measure of oneself/to overrate one's own abilities

Example

As a Verb

not take a proper measure of oneself; overestimate/overrate one's own abilities

1
Cǐrén
此人
hěn
很
bù
不
zìliàng
自量
  
,
cháng
常
yǐ
以
zhuānjiā
专家
zìjū
自居
  
。

That guy far overestimated his own abilities and often rated himself as an expert.

2
Pífúhàndàshù
蚍蜉撼大树
  
,
kěxiào
可笑
bù
不
zì
自
liàng
量

ridiculously overrate oneself as a mayfly trying to topple a giant tree