diff --git a/index.html b/index.html
index be009cf..6c268af 100644
--- a/index.html
+++ b/index.html
@@ -43,6 +43,11 @@
          margin: 0.2rem 0;
      }
 
+     label > span {
+         display: inline-block;
+         width: 9em;
+     }
+
      @media screen and (min-width: 1024px) {
          div.container {
              display: grid;
diff --git a/src/main.ts b/src/main.ts
index 1a63996..c367a55 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -114,6 +114,9 @@ const scene = sync({
 const input = (label: string, attrs: any) =>
   ["div", {}, ["label", {}, label, ["input", attrs]]]
 
+const select = (label: string, attrs: any, options: string[]) =>
+  ["div", {}, ["label", {}, label, ["select", attrs, ...options.map(u => ["option", {value: u}, u])]]]
+
 $compile(
   ["div.container", {},
    ["main", {},
@@ -133,6 +136,7 @@ $compile(
       value: height.deref()!,
       oninput: $inputNum(height),
     }),
+    select("Unit", { oninput: $input(unit) }, ["mm", "px"]),
     input("Grid size: ", {
       type: "number",
       min: "5",