diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..c25db83
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,9 @@
+export function parse(value: string | number, property?: string): {
+  'value': number,
+  'unit': string
+};
+
+export function convert(to: string, value: string, element?: Element, property?: string): number;
+
+export function getDefaultValue(property: string): number;
+export function getDefaultUnit(property: string): string;