diff --git a/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSS.kt b/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSS.kt
index 8ab5de8f66..be350d3c22 100644
--- a/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSS.kt
+++ b/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSS.kt
@@ -142,8 +142,10 @@ external interface CSSNumericValue : CSSStyleValue {
 //    }
 }
 
-open class CSSUnitValue(val value: Number, val unit: String) : CSSNumericValue {
-    override fun toString(): String = "${value}${unit}"
+interface CSSUnitValue : CSSNumericValue {
+    val value: Number
+    val unit: String
+    fun asString(): String = "${value}${unit}"
 }
 
 // declare enum CSSMathOperator {
@@ -329,7 +331,7 @@ external interface StylePropertyValue
 fun String.asStylePropertyValue() = unsafeCast<StylePropertyValue>()
 fun Number.asStylePropertyValue() = unsafeCast<StylePropertyValue>()
 fun CSSStyleValue.asStylePropertyValue() = unsafeCast<StylePropertyValue>()
-fun CSSUnitValue.asStylePropertyValue() = toString().asStylePropertyValue()
+fun CSSUnitValue.asStylePropertyValue() = asString().asStylePropertyValue()
 
 external class StylePropertyMap : StylePropertyMapReadOnly {
     fun set(property: String, vararg values: StylePropertyValue)
diff --git a/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSProperties.kt b/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSProperties.kt
index 400cacaf5f..db03363241 100644
--- a/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSProperties.kt
+++ b/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSProperties.kt
@@ -296,7 +296,7 @@ fun StyleBuilder.borderRadius(r: CSSUnitValue) {
 }
 
 fun StyleBuilder.borderRadius(topLeft: CSSUnitValue, bottomRight: CSSUnitValue) {
-    property("border-radius", "$topLeft $bottomRight".asStylePropertyValue())
+    property("border-radius", "${topLeft.asString()} ${bottomRight.asString()}".asStylePropertyValue())
 }
 
 fun StyleBuilder.borderRadius(
@@ -304,7 +304,7 @@ fun StyleBuilder.borderRadius(
     topRightAndBottomLeft: CSSUnitValue,
     bottomRight: CSSUnitValue
 ) {
-    property("border-radius", "$topLeft $topRightAndBottomLeft $bottomRight".asStylePropertyValue())
+    property("border-radius", "${topLeft.asString()} ${topRightAndBottomLeft.asString()} ${bottomRight.asString()}".asStylePropertyValue())
 }
 
 fun StyleBuilder.borderRadius(
@@ -313,7 +313,10 @@ fun StyleBuilder.borderRadius(
     bottomRight: CSSUnitValue,
     bottomLeft: CSSUnitValue
 ) {
-    property("border-radius", "$topLeft $topRight $bottomRight $bottomLeft".asStylePropertyValue())
+    property(
+        "border-radius",
+        "${topLeft.asString()} ${topRight.asString()} ${bottomRight.asString()} ${bottomLeft.asString()}".asStylePropertyValue()
+    )
 }
 
 fun StyleBuilder.width(value: CSSUnitValue) {
@@ -370,18 +373,18 @@ fun StyleBuilder.fontSize(value: CSSUnitValue) {
 
 fun StyleBuilder.margin(value: CSSUnitValue) {
     // marign hasn't Typed OM yet
-    property("margin", value(value.toString()))
+    property("margin", value(value.asString()))
 }
 
 fun StyleBuilder.marginLeft(value: CSSUnitValue) {
-    property("margin-left", value(value.toString()))
+    property("margin-left", value(value.asString()))
 }
 
 fun StyleBuilder.marginTop(value: CSSUnitValue) {
-    property("margin-top", value(value.toString()))
+    property("margin-top", value(value.asString()))
 }
 
 fun StyleBuilder.padding(value: CSSUnitValue) {
     // padding hasn't Typed OM yet
-    property("padding", value(value.toString()))
+    property("padding", value(value.asString()))
 }
diff --git a/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSUnits.kt b/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSUnits.kt
index 27e73db800..9d639f4a49 100644
--- a/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSUnits.kt
+++ b/web/core/src/jsMain/kotlin/androidx/compose/web/css/CSSUnits.kt
@@ -8,47 +8,173 @@ interface CSSFrequencyValue
 interface CSSResolutionValue
 interface CSSFlexValue
 
-class CSSpercentValue(value: Number) : CSSUnitValue(value, "percent"), CSSRelValue
-class CSSemValue(value: Number) : CSSUnitValue(value, "em"), CSSRelValue
-class CSSexValue(value: Number) : CSSUnitValue(value, "ex"), CSSRelValue
-class CSSchValue(value: Number) : CSSUnitValue(value, "ch"), CSSRelValue
-class CSSicValue(value: Number) : CSSUnitValue(value, "ic"), CSSRelValue
-class CSSremValue(value: Number) : CSSUnitValue(value, "rem"), CSSRelValue
-class CSSlhValue(value: Number) : CSSUnitValue(value, "lh"), CSSRelValue
-class CSSrlhValue(value: Number) : CSSUnitValue(value, "rlh"), CSSRelValue
-class CSSvwValue(value: Number) : CSSUnitValue(value, "vw"), CSSRelValue
-class CSSvhValue(value: Number) : CSSUnitValue(value, "vh"), CSSRelValue
-class CSSviValue(value: Number) : CSSUnitValue(value, "vi"), CSSRelValue
-class CSSvbValue(value: Number) : CSSUnitValue(value, "vb"), CSSRelValue
-class CSSvminValue(value: Number) : CSSUnitValue(value, "vmin"), CSSRelValue
-class CSSvmaxValue(value: Number) : CSSUnitValue(value, "vmax"), CSSRelValue
-class CSScmValue(value: Number) : CSSUnitValue(value, "cm"), CSSRelValue
-class CSSmmValue(value: Number) : CSSUnitValue(value, "mm"), CSSRelValue
-class CSSQValue(value: Number) : CSSUnitValue(value, "q"), CSSRelValue
-
-class CSSptValue(value: Number) : CSSUnitValue(value, "pt"), CSSAbsValue
-class CSSpcValue(value: Number) : CSSUnitValue(value, "pc"), CSSAbsValue
-class CSSpxValue(value: Number) : CSSUnitValue(value, "px"), CSSAbsValue
-
-class CSSdegValue(value: Number) : CSSUnitValue(value, "deg"), CSSAngleValue
-class CSSgradValue(value: Number) : CSSUnitValue(value, "grad"), CSSAngleValue
-class CSSradValue(value: Number) : CSSUnitValue(value, "rad"), CSSAngleValue
-class CSSturnValue(value: Number) : CSSUnitValue(value, "turn"), CSSAngleValue
-
-class CSSsValue(value: Number) : CSSUnitValue(value, "s"), CSSTimeValue
-class CSSmsValue(value: Number) : CSSUnitValue(value, "ms"), CSSTimeValue
-
-class CSSHzValue(value: Number) : CSSUnitValue(value, "hz"), CSSFrequencyValue
-class CSSkHzValue(value: Number) : CSSUnitValue(value, "khz"), CSSFrequencyValue
-
-class CSSdpiValue(value: Number) : CSSUnitValue(value, "dpi"), CSSResolutionValue
-class CSSdpcmValue(value: Number) : CSSUnitValue(value, "dpcm"), CSSResolutionValue
-class CSSdppxValue(value: Number) : CSSUnitValue(value, "dppx"), CSSResolutionValue
-
-class CSSfrValue(value: Number) : CSSUnitValue(value, "fr"), CSSFlexValue
+class CSSpercentValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "percent"
+}
+
+class CSSemValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "em"
+}
+
+class CSSexValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "ex"
+}
+
+class CSSchValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "ch"
+}
+
+class CSSicValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "ic"
+}
+
+class CSSremValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "rem"
+}
+
+class CSSlhValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "lh"
+}
+
+class CSSrlhValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "rlh"
+}
+
+class CSSvwValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "vw"
+}
+
+class CSSvhValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "vh"
+}
+
+class CSSviValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "vi"
+}
+
+class CSSvbValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "vb"
+}
+
+class CSSvminValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "vmin"
+}
+
+class CSSvmaxValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "vmax"
+}
+
+class CSScmValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "cm"
+}
+
+class CSSmmValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "mm"
+}
+
+class CSSQValue(override val value: Number) : CSSUnitValue, CSSRelValue {
+    override val unit: String
+        get() = "q"
+}
+
+class CSSptValue(override val value: Number) : CSSUnitValue, CSSAbsValue {
+    override val unit: String
+        get() = "pt"
+}
+
+class CSSpcValue(override val value: Number) : CSSUnitValue, CSSAbsValue {
+    override val unit: String
+        get() = "pc"
+}
+
+class CSSpxValue(override val value: Number) : CSSUnitValue, CSSAbsValue {
+    override val unit: String
+        get() = "px"
+}
+
+class CSSdegValue(override val value: Number) : CSSUnitValue, CSSAngleValue {
+    override val unit: String
+        get() = "deg"
+}
+
+class CSSgradValue(override val value: Number) : CSSUnitValue, CSSAngleValue {
+    override val unit: String
+        get() = "grad"
+}
+
+class CSSradValue(override val value: Number) : CSSUnitValue, CSSAngleValue {
+    override val unit: String
+        get() = "rad"
+}
+
+class CSSturnValue(override val value: Number) : CSSUnitValue, CSSAngleValue {
+    override val unit: String
+        get() = "turn"
+}
+
+class CSSsValue(override val value: Number) : CSSUnitValue, CSSTimeValue {
+    override val unit: String
+        get() = "s"
+}
+
+class CSSmsValue(override val value: Number) : CSSUnitValue, CSSTimeValue {
+    override val unit: String
+        get() = "ms"
+}
+
+class CSSHzValue(override val value: Number) : CSSUnitValue, CSSFrequencyValue {
+    override val unit: String
+        get() = "hz"
+}
+
+class CSSkHzValue(override val value: Number) : CSSUnitValue, CSSFrequencyValue {
+    override val unit: String
+        get() = "khz"
+}
+
+class CSSdpiValue(override val value: Number) : CSSUnitValue, CSSResolutionValue {
+    override val unit: String
+        get() = "dpi"
+}
+
+class CSSdpcmValue(override val value: Number) : CSSUnitValue, CSSResolutionValue {
+    override val unit: String
+        get() = "dpcm"
+}
+
+class CSSdppxValue(override val value: Number) : CSSUnitValue, CSSResolutionValue {
+    override val unit: String
+        get() = "dppx"
+}
+
+class CSSfrValue(override val value: Number) : CSSUnitValue, CSSFlexValue {
+    override val unit: String
+        get() = "fr"
+}
+
+class CSSnumberValue(override val value: Number) : CSSUnitValue, CSSFlexValue {
+    override val unit: String
+    get() = "number"
+}
 
 val Number.number
-    get(): CSSUnitValue = CSSUnitValue(this, "number")
+    get(): CSSUnitValue = CSSnumberValue(this)
 
 val Number.percent
     get(): CSSpercentValue = CSSpercentValue(this)
diff --git a/web/core/src/jsTest/kotlin/CSSUnitApiTests.kt b/web/core/src/jsTest/kotlin/CSSUnitApiTests.kt
index 946753ed1e..ccf348d194 100644
--- a/web/core/src/jsTest/kotlin/CSSUnitApiTests.kt
+++ b/web/core/src/jsTest/kotlin/CSSUnitApiTests.kt
@@ -18,6 +18,7 @@ import org.jetbrains.compose.web.css.CSSfrValue
 import org.jetbrains.compose.web.css.CSSgradValue
 import org.jetbrains.compose.web.css.CSSmmValue
 import org.jetbrains.compose.web.css.CSSmsValue
+import org.jetbrains.compose.web.css.CSSnumberValue
 import org.jetbrains.compose.web.css.CSSpcValue
 import org.jetbrains.compose.web.css.CSSpercentValue
 import org.jetbrains.compose.web.css.CSSptValue
@@ -109,7 +110,7 @@ class CSSUnitApiTests {
 
     @Test
     fun postfixInvocation() {
-        4.number.assertStructure(CSSUnitValue(4, "number"), "number postfix")
+        4.number.assertStructure(CSSnumberValue(4), "number postfix")
         4.percent.assertStructure(CSSpercentValue(4), "percent posfix")
 
         4.em.assertStructure(CSSemValue(4), "em postfix")