out of proportion
Also, out of all proportion. Not in proper relation to other things, especially by being the wrong size or amount. For example, This vase looks out of proportion on this small table, or Her emotional response was out of all proportion to the circumstances. The noun proportion means “an agreeable or harmonious relationship of one thing relative to another.” [Early 1700s] The antonym in proportion dates from the late 1600s and also refers either to physical size or appropriate degree, as in The bird's wings are huge in proportion to its body, or Her willingness to believe him stands in direct proportion to her love for intrigue.
Examples from the Web for out of proportion
There was nothing malformed nor out-of-proportion; yet he spoke with an adult air of confidence.The Fourth R|George Oliver Smith