diff --git a/js-quantities/js-quantities-tests.ts b/js-quantities/js-quantities-tests.ts
new file mode 100644
index 0000000000..c8d00eef53
--- /dev/null
+++ b/js-quantities/js-quantities-tests.ts
@@ -0,0 +1,9 @@
+/// <reference path="js-quantities.d.ts" />
+
+var Val1 = Qty('1 m')
+
+var Val2 = Qty(1);
+
+var Val3 = Qty(1, 'm');
+
+var Val4 = Qty(Val1);
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diff --git a/js-quantities/js-quantities.d.ts b/js-quantities/js-quantities.d.ts
new file mode 100644
index 0000000000..a2e3c2d96c
--- /dev/null
+++ b/js-quantities/js-quantities.d.ts
@@ -0,0 +1,79 @@
+// Type definitions for JS-quantities
+// Project: http://gentooboontoo.github.io/js-quantities/
+// Definitions by: William Comartin <https://github.com/wcomartin>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+declare var Qty: QtyModule.QtyStatic;
+
+declare namespace QtyModule {
+  interface QtyStatic {
+    (value: string): Qty;
+    (value: number): Qty;
+    (value: number, unit: string): Qty;
+    (value: Qty): Qty;
+  }
+
+  interface Qty {
+    version: string;
+
+    scalar: number;
+    baseScalar: number;
+
+    parse(value: string): Qty;
+
+    swiftConverter(srcUnits:string, dstUnits:string): (value:number) => number;
+
+    getkinds(): string[];
+
+    getUnits(kind:string): string[];
+
+    getAliases(unitName:string): string[];
+
+    formatter(scalar:number, units:string):string;
+
+    toFloat(): number;
+
+    isUnitless(): boolean;
+
+    isCompatible(other:string|Qty): boolean;
+
+    isInverse(other:string|Qty): boolean
+
+    kind(): string;
+
+    isBase(): boolean;
+
+    toBase(): Qty;
+
+    units(): string;
+
+    eq(other:Qty): boolean;
+    lt(other:Qty): boolean;
+    lte(other:Qty): boolean;
+    gt(other:Qty): boolean;
+    gte(other:Qty): boolean;
+
+    toPrec(precQuantity: Qty|string|number): Qty;
+
+    toString(targetUnitsOrMaxDecimalsOrPrec?:number|string|Qty, maxDecimals?: number): string;
+
+    format(targetUnits?:string, formatter?:(scalar:number, units:string) => string): string;
+
+    compareTo(other:Qty|string): number;
+
+    same(other: Qty): boolean;
+
+    inverse(): Qty;
+
+    isDegrees(): boolean;
+
+    isTemperature(): boolean;
+
+    to(other:string|Qty): Qty;
+
+    add(other:string|Qty): Qty;
+    sub(other:string|Qty): Qty;
+    mul(other:number|string|Qty): Qty;
+    div(other:number|string|Qty): Qty;
+  }
+}
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