diff --git a/src/datachunk.h b/src/datachunk.h
new file mode 100644
--- /dev/null
+++ b/src/datachunk.h
@@ -0,0 +1,57 @@
+/*
+  Copyright © 2017 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef DATACHUNK_H
+#define DATACHUNK_H
+
+class DataChunk
+{
+public:
+    DataChunk(size_t start, size_t capacity);
+    ~DataChunk();
+
+    size_t start() const;       // index of first element
+    size_t end() const;         // index after last element
+    size_t size() const;        // fill size
+    size_t capacity() const;    // set capacity
+    bool isFull() const;
+    size_t left() const;
+
+    double min() const;
+    double max() const;
+    double avg() const;
+    double meanSquare() const;
+
+    void addSamples(double* samples, size_t size);
+    double sample(size_t i) const;
+
+private:
+    size_t _start;
+    size_t _capacity;
+    size_t _size;
+
+    double _min;
+    double _max;
+    double _sum;
+    double _sumSquare;          // sum of squares
+
+    double* _samples;
+};
+
+#endif // DATACHUNK_H