use function floatcmp; $a = 0.00528690; $b = 0.00528; if (floatcmp($a, $b, 5) === 0) { /*  * $a and $b are equal at given scale precision.  *  * Unlike a floating-point arithmetic library,  * floatcmp() does not apply rounding to its  * arguments but instead takes a fixed-width  * scale approach like bccomp(). When bcmath  * is available, floatcmp() will use bccomp()  * for the float comparison.  */ }