diff --git a/mainwindow.cpp b/mainwindow.cpp
index b2e5692..dd31c9b 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -35,6 +35,7 @@ MainWindow::MainWindow()
     setCentralWidget(plots);
 
     connect(dock, SIGNAL(fftSizeChanged(int)), plots, SLOT(setFFTSize(int)));
+    connect(dock->zoomLevelSlider, SIGNAL(valueChanged(int)), plots, SLOT(setZoomLevel(int)));
 }
 
 void MainWindow::openFile(QString fileName)
diff --git a/plotview.cpp b/plotview.cpp
index fdb75a7..aec5c28 100644
--- a/plotview.cpp
+++ b/plotview.cpp
@@ -112,6 +112,15 @@ void PlotView::setFFTSize(int size)
 {
     fftSize = size;
     spectrogramPlot->setFFTSize(size);
+    horizontalScrollBar()->setSingleStep(size * pow(2, zoomLevel));
+    horizontalScrollBar()->setPageStep(size * pow(2, zoomLevel) * 10);
+    viewport()->update();
+}
+
+void PlotView::setZoomLevel(int zoom)
+{
+    zoomLevel = zoom;
+    spectrogramPlot->setZoomLevel(zoom);
     viewport()->update();
 }
 
@@ -119,8 +128,7 @@ void PlotView::paintEvent(QPaintEvent *event)
 {
     if (mainSampleSource == nullptr) return;
     off_t firstSample = horizontalScrollBar()->value();
-    // TODO: don't hardcode width
-    off_t lastSample = firstSample + fftSize * width();
+    off_t lastSample = firstSample + fftSize * width() / pow(2, zoomLevel);
 
     QRect rect = QRect(0, 0, width(), height());
     QPainter painter(viewport());
diff --git a/plotview.h b/plotview.h
index ffa5ed2..8caeee5 100644
--- a/plotview.h
+++ b/plotview.h
@@ -37,6 +37,7 @@ public slots:
     void selectionChanged(std::pair<off_t, off_t> selectionTime, std::pair<float, float> selectionFreq);
     void selectionCleared();
     void setFFTSize(int size);
+    void setZoomLevel(int zoom);
 
 protected:
     void paintEvent(QPaintEvent *event);
@@ -50,6 +51,7 @@ private:
     std::pair<float, float> selectionFreq;
 
     int fftSize;
+    int zoomLevel;
 
     void refreshSources();
 };
\ No newline at end of file
diff --git a/spectrogramplot.cpp b/spectrogramplot.cpp
index 5e519a9..295d1c0 100644
--- a/spectrogramplot.cpp
+++ b/spectrogramplot.cpp
@@ -118,7 +118,7 @@ void SpectrogramPlot::mousePressEvent(QMouseEvent *event)
 void SpectrogramPlot::paintMid(QPainter &painter, QRect &rect, range_t<off_t> sampleRange)
 {
     for (int x = rect.left(); x < rect.right(); x += linesPerTile()) {
-        QPixmap *tile = getPixmapTile(x * fftSize);
+        QPixmap *tile = getPixmapTile(sampleRange.minimum + x * getStride());
         painter.drawPixmap(QRect(x, rect.y(), linesPerTile(), fftSize), *tile);
     }
 }