diff --git a/docs/api-input.md b/docs/api-input.md
index f15677b6..067d5c06 100644
--- a/docs/api-input.md
+++ b/docs/api-input.md
@@ -25,6 +25,7 @@ Fast access to (uncached) image metadata without decoding any compressed image d
 A Promises/A+ promise is returned when `callback` is not provided.
 
 -   `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
+-   `size`: Total size of image in bytes, for Stream and Buffer input only
 -   `width`: Number of pixels wide (EXIF orientation is not taken into consideration)
 -   `height`: Number of pixels high (EXIF orientation is not taken into consideration)
 -   `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...][1]
diff --git a/docs/changelog.md b/docs/changelog.md
index 348a78cf..37cd3ce9 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -19,6 +19,9 @@ Requires libvips v8.7.0.
     Per-operation `background` options added to `resize`, `extend` and `flatten` operations.
   [#1392](https://github.com/lovell/sharp/issues/1392)
 
+* Add `size` to `metadata` response (Stream and Buffer input only).
+  [#695](https://github.com/lovell/sharp/issues/695)
+
 * Switch from custom trim operation to `vips_find_trim`.
   [#914](https://github.com/lovell/sharp/issues/914)
 
diff --git a/lib/input.js b/lib/input.js
index 5850f76b..fcfbba73 100644
--- a/lib/input.js
+++ b/lib/input.js
@@ -177,6 +177,7 @@ function clone () {
  * A Promises/A+ promise is returned when `callback` is not provided.
  *
  * - `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
+ * - `size`: Total size of image in bytes, for Stream and Buffer input only
  * - `width`: Number of pixels wide (EXIF orientation is not taken into consideration)
  * - `height`: Number of pixels high (EXIF orientation is not taken into consideration)
  * - `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/libvips/libvips/blob/master/libvips/iofuncs/enumtypes.c#L636)
diff --git a/src/metadata.cc b/src/metadata.cc
index 12490d1d..394209f2 100644
--- a/src/metadata.cc
+++ b/src/metadata.cc
@@ -123,6 +123,9 @@ class MetadataWorker : public Nan::AsyncWorker {
       // Metadata Object
       v8::Local<v8::Object> info = New<v8::Object>();
       Set(info, New("format").ToLocalChecked(), New<v8::String>(baton->format).ToLocalChecked());
+      if (baton->input->bufferLength > 0) {
+        Set(info, New("size").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(baton->input->bufferLength)));
+      }
       Set(info, New("width").ToLocalChecked(), New<v8::Uint32>(baton->width));
       Set(info, New("height").ToLocalChecked(), New<v8::Uint32>(baton->height));
       Set(info, New("space").ToLocalChecked(), New<v8::String>(baton->space).ToLocalChecked());
diff --git a/test/unit/metadata.js b/test/unit/metadata.js
index 569d12f3..b846a0c4 100644
--- a/test/unit/metadata.js
+++ b/test/unit/metadata.js
@@ -13,6 +13,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputJpg).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
       assert.strictEqual('srgb', metadata.space);
@@ -34,6 +35,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputJpgWithExif).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(450, metadata.width);
       assert.strictEqual(600, metadata.height);
       assert.strictEqual('srgb', metadata.space);
@@ -83,6 +85,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputTiff).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('tiff', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2464, metadata.width);
       assert.strictEqual(3248, metadata.height);
       assert.strictEqual('b-w', metadata.space);
@@ -104,6 +107,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputPng).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('png', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2809, metadata.width);
       assert.strictEqual(2074, metadata.height);
       assert.strictEqual('b-w', metadata.space);
@@ -125,6 +129,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputPngWithTransparency).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('png', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2048, metadata.width);
       assert.strictEqual(1536, metadata.height);
       assert.strictEqual('srgb', metadata.space);
@@ -146,6 +151,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputWebP).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('webp', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(1024, metadata.width);
       assert.strictEqual(772, metadata.height);
       assert.strictEqual('srgb', metadata.space);
@@ -167,6 +173,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputGif).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('gif', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(800, metadata.width);
       assert.strictEqual(533, metadata.height);
       assert.strictEqual(3, metadata.channels);
@@ -186,6 +193,7 @@ describe('Image metadata', function () {
     sharp(fixtures.inputGifGreyPlusAlpha).metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('gif', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2, metadata.width);
       assert.strictEqual(1, metadata.height);
       assert.strictEqual(2, metadata.channels);
@@ -205,6 +213,7 @@ describe('Image metadata', function () {
   it('File in, Promise out', function (done) {
     sharp(fixtures.inputJpg).metadata().then(function (metadata) {
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
       assert.strictEqual('srgb', metadata.space);
@@ -236,6 +245,7 @@ describe('Image metadata', function () {
     const pipeline = sharp();
     pipeline.metadata().then(function (metadata) {
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual(829183, metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
       assert.strictEqual('srgb', metadata.space);
@@ -250,9 +260,7 @@ describe('Image metadata', function () {
       assert.strictEqual('undefined', typeof metadata.exif);
       assert.strictEqual('undefined', typeof metadata.icc);
       done();
-    }).catch(function (err) {
-      throw err;
-    });
+    }).catch(done);
     readable.pipe(pipeline);
   });
 
@@ -261,6 +269,7 @@ describe('Image metadata', function () {
     const pipeline = sharp().metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual(829183, metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
       assert.strictEqual('srgb', metadata.space);
@@ -284,6 +293,7 @@ describe('Image metadata', function () {
     image.metadata(function (err, metadata) {
       if (err) throw err;
       assert.strictEqual('jpeg', metadata.format);
+      assert.strictEqual('undefined', typeof metadata.size);
       assert.strictEqual(2725, metadata.width);
       assert.strictEqual(2225, metadata.height);
       assert.strictEqual('srgb', metadata.space);