diff --git a/src/index.js b/src/index.js
index 510103c..ba317c7 100644
--- a/src/index.js
+++ b/src/index.js
@@ -8,7 +8,8 @@ export {
 } from "./identity.js";
 
 export {
-  default as scaleLinear
+  default as scaleLinear,
+  pad as padLinear
 } from "./linear.js";
 
 export {
diff --git a/src/linear.js b/src/linear.js
index b91f712..d52efca 100644
--- a/src/linear.js
+++ b/src/linear.js
@@ -70,3 +70,8 @@ export default function linear() {
 
   return linearish(scale);
 }
+
+export function pad([x0, x1], k) {
+  var dx = (x1 - x0) * k / 2;
+  return [x0 - dx, x1 + dx];
+}
diff --git a/test/linear-test.js b/test/linear-test.js
index 62de558..e239552 100644
--- a/test/linear-test.js
+++ b/test/linear-test.js
@@ -509,3 +509,9 @@ tape("linear.copy() returns a copy with changes to the unknown value are isolate
   test.equal(x.unknown(), 2);
   test.end();
 });
+
+tape("padLinear returns a padded domain array", function(test) {
+  test.deepEqual(scale.padLinear([0, 8], 0.5), [-2, 10])
+  test.deepEqual(scale.padLinear([0, 8], 0.25), [-1, 9])
+  test.end();
+});