Kalmar "factor of proportionality" tana nufin ƙima akai-akai wanda ke da alaƙa da adadi biyu waɗanda suke daidai da juna kai tsaye. Ma’ana, idan ma’aunai biyu sun yi daidai da juna, to rabon ma’auni biyun ya tsaya tsayin daka kuma wannan akai ana kiransa factor of proportionality. Misali, idan y ya yi daidai da x, to, ma'aunin daidaito tsakanin y da x shine akai k kamar y = kx.
