diff --git a/main.go b/main.go
index a367d14..4343cc3 100644
--- a/main.go
+++ b/main.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 
@@ -133,6 +134,28 @@ func (d *Downloader) downloadFileWithTimeout(userCtx context.Context, u string)
 	}
 }
 
+func (d *Downloader) getDownloadSize(ctx context.Context, u string) (uint64, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodHead, u, nil)
+	if err != nil {
+		return 0, fmt.Errorf("creating the request for %s: %w", u, err)
+	}
+	resp, err := d.client.Do(req)
+	if err != nil {
+		return 0, fmt.Errorf("sending get http request to %s: %w", u, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 200 {
+		return 0, fmt.Errorf("got unexpected http response status for %s: %s", u, resp.Status)
+	}
+	if resp.ContentLength <= 0 && resp.Header.Get("Content-Range") != "" {
+		var s uint64
+		p := strings.Split(resp.Header.Get("Content-Range"), "/")
+		fmt.Sscan(p[len(p)-1], &s)
+		return s, nil
+	}
+	return uint64(resp.ContentLength), nil
+}
+
 func (d *Downloader) downloadFile(ctx context.Context, u string) ([]byte, error) {
 	ch := make(chan []byte, 1)
 	defer close(ch)
@@ -193,9 +216,16 @@ func (d *Downloader) DownloadWithContext(ctx context.Context, urls ...string) <-
 		wg.Add(1)
 		go func(u string) {
 			defer wg.Done()
-			s := DownloadStatus{URL: u}
+			path := filepath.Join(os.TempDir(), filepath.Base(u))
+			s := DownloadStatus{URL: u, DownloadedFilePath: path}
 			defer func() { ch <- s }()
-			s.DownloadedFilePath = filepath.Join(os.TempDir(), filepath.Base(u))
+			t, err := d.getDownloadSize(ctx, u) // TODO: retry
+			if err != nil {
+				s.Error = fmt.Errorf("error getting file size: %w", err)
+				return
+			}
+			s.FileSizeBytes = t
+			ch <- s // send total file size to the user
 			b, err := d.downloadFile(ctx, u)
 			if err != nil {
 				s.Error = err
@@ -206,7 +236,6 @@ func (d *Downloader) DownloadWithContext(ctx context.Context, urls ...string) <-
 				return
 			}
 			s.DownloadedFileBytes = uint64(len(b))
-			s.FileSizeBytes = uint64(len(b))
 		}(u)
 	}
 	go func() {
diff --git a/main_test.go b/main_test.go
index 1a1f473..96f9cec 100644
--- a/main_test.go
+++ b/main_test.go
@@ -24,6 +24,9 @@ func TestDownload_Error(t *testing.T) {
 		t.Run(tc.desc, func(t *testing.T) {
 			s := httptest.NewServer(http.HandlerFunc(
 				func(w http.ResponseWriter, r *http.Request) {
+					if r.Method == http.MethodHead {
+						return
+					}
 					tc.proc(w)
 				},
 			))
@@ -36,11 +39,12 @@ func TestDownload_Error(t *testing.T) {
 				WaitBetweenRetries:            0 * time.Second,
 			}
 			ch := d.Download(s.URL)
-			status := <-ch
-			if status.Error == nil {
+			<-ch // discard the first got (just the file size)
+			got := <-ch
+			if got.Error == nil {
 				t.Error("expected an error, but got nil")
 			}
-			if !strings.Contains(status.Error.Error(), "#4") {
+			if !strings.Contains(got.Error.Error(), "#4") {
 				t.Error("expected #4 (configured number of retries), but did not get it")
 			}
 			if _, ok := <-ch; ok {
@@ -59,6 +63,7 @@ func TestDownload_OkWithDefaultDownloader(t *testing.T) {
 	defer s.Close()
 
 	ch := DefaultDownloader().Download(s.URL)
+	<-ch // discard the first status (just the file size)
 	got := <-ch
 	defer os.Remove(got.DownloadedFilePath)
 
@@ -99,6 +104,10 @@ func TestDownload_Retry(t *testing.T) {
 			attempts := int32(0)
 			s := httptest.NewServer(http.HandlerFunc(
 				func(w http.ResponseWriter, r *http.Request) {
+					if r.Method == http.MethodHead {
+						w.Header().Add("Content-Length", "2")
+						return
+					}
 					if atomic.CompareAndSwapInt32(&attempts, 0, 1) {
 						tc.proc(w)
 					}
@@ -115,6 +124,7 @@ func TestDownload_Retry(t *testing.T) {
 				WaitBetweenRetries:            0 * time.Second,
 			}
 			ch := d.Download(s.URL)
+			<-ch // discard the first status (just the file size)
 			got := <-ch
 			if got.Error != nil {
 				t.Errorf("invalid error. want:nil got:%q", got.Error)
@@ -150,6 +160,9 @@ func TestDownloadWithContext_ErrorUserTimeout(t *testing.T) {
 	timeout := 10 * userTimeout
 	s := httptest.NewServer(http.HandlerFunc(
 		func(w http.ResponseWriter, r *http.Request) {
+			if r.Method == http.MethodHead {
+				return
+			}
 			time.Sleep(2 * userTimeout) // this time is greater than the user timeout, but shorter than the timeout per chunk.
 		},
 	))
@@ -165,11 +178,12 @@ func TestDownloadWithContext_ErrorUserTimeout(t *testing.T) {
 	defer cancFunc()
 
 	ch := d.DownloadWithContext(userCtx, s.URL)
-	status := <-ch
-	if status.Error == nil {
+	<-ch // discard the first got (just the file size)
+	got := <-ch
+	if got.Error == nil {
 		t.Error("expected an error, but got nil")
 	}
-	if !strings.Contains(status.Error.Error(), "#4") {
+	if !strings.Contains(got.Error.Error(), "#4") {
 		t.Error("expected #4 (configured number of retries), but did not get it")
 	}
 	if _, ok := <-ch; ok {
@@ -202,3 +216,5 @@ func TestDownload_Chunks(t *testing.T) {
 		}
 	}
 }
+
+// TODO: add tests for getDownloadSize (success with Content-Length, success with Content-Range, failure)