diff --git a/src/ui/model/traflistmodel.cpp b/src/ui/model/traflistmodel.cpp
index 40171647..bc51580f 100644
--- a/src/ui/model/traflistmodel.cpp
+++ b/src/ui/model/traflistmodel.cpp
@@ -191,15 +191,6 @@ bool TrafListModel::updateTableRow(const QVariantHash & /*vars*/, int row) const
 
 QString TrafListModel::formatTrafUnit(qint64 bytes) const
 {
-    static const QVector<qint64> unitMults = {
-        1, // Adaptive
-        1, // Bytes
-        1024, // KB
-        1024 * 1024, // MB
-        qint64(1024) * 1024 * 1024, // GB
-        qint64(1024) * 1024 * 1024 * 1024 // TB
-    };
-
     if (bytes == 0) {
         return QLatin1String("0");
     }
@@ -210,9 +201,9 @@ QString TrafListModel::formatTrafUnit(qint64 bytes) const
         return FormatUtil::formatDataSize(bytes, trafPrec);
     }
 
-    const qint64 unitMult = unitMults.at(unit());
+    const int power = unit() - 1;
 
-    return QLocale().toString(qreal(bytes) / unitMult, 'f', trafPrec);
+    return FormatUtil::formatSize(bytes, power, trafPrec);
 }
 
 QString TrafListModel::formatTrafTime(qint32 trafTime) const
diff --git a/src/ui/model/traflistmodel.h b/src/ui/model/traflistmodel.h
index 1ed64de1..870d635c 100644
--- a/src/ui/model/traflistmodel.h
+++ b/src/ui/model/traflistmodel.h
@@ -17,7 +17,7 @@ class TrafListModel : public TableItemModel
     Q_OBJECT
 
 public:
-    enum TrafUnit { UnitAdaptive = 0, UnitBytes, UnitKB, UnitMB, UnitGB, UnitTB };
+    enum TrafUnit { UnitAdaptive = 0, UnitBytes, UnitKB, UnitMB, UnitGB, UnitTB, UnitPB, UnitEB };
     Q_ENUM(TrafUnit)
 
     enum TrafType { TrafHourly = 0, TrafDaily, TrafMonthly, TrafTotal };
diff --git a/src/ui/util/formatutil.cpp b/src/ui/util/formatutil.cpp
index ca4deb3e..049e5818 100644
--- a/src/ui/util/formatutil.cpp
+++ b/src/ui/util/formatutil.cpp
@@ -1,5 +1,48 @@
 #include "formatutil.h"
 
+namespace {
+
+static const qint64 g_baseSiPowerValues[] = {
+    1,
+    1024LL, // kilo
+    1024LL * 1024LL, // mega
+    1024LL * 1024LL * 1024LL, // giga
+    1024LL * 1024LL * 1024LL * 1024LL, // tera
+    1024LL * 1024LL * 1024LL * 1024LL * 1024LL, // peta
+    1024LL * 1024LL * 1024LL * 1024LL * 1024LL * 1024LL, // exa
+};
+
+static const qint64 g_baseIecPowerValues[] = {
+    1,
+    1000LL, // kibi
+    1000LL * 1000LL, // mebi
+    1000LL * 1000LL * 1000LL, // gibi
+    1000LL * 1000LL * 1000LL * 1000LL, // tebi
+    1000LL * 1000LL * 1000LL * 1000LL * 1000LL, // pebi
+    1000LL * 1000LL * 1000LL * 1000LL * 1000LL * 1000LL, // exbi
+};
+
+constexpr int FORMAT_POWER_VALUES_SIZE = 7;
+
+static_assert(
+        std::size(g_baseSiPowerValues) == FORMAT_POWER_VALUES_SIZE, "powerValues size mismatch");
+
+}
+
+QString FormatUtil::formatSize(
+        qint64 value, int power, int precision, QLocale::DataSizeFormats format)
+{
+    // We don't support sizes in units larger than exbibytes because
+    // the number of bytes would not fit into qint64.
+    Q_ASSERT(power < FORMAT_POWER_VALUES_SIZE && power >= 0);
+
+    const qint64 *powerValues =
+            (format & QLocale::DataSizeBase1000) ? g_baseIecPowerValues : g_baseSiPowerValues;
+    const qint64 powerValue = powerValues[power];
+
+    return QLocale().toString(qreal(value) / powerValue, 'f', precision);
+}
+
 QString FormatUtil::formatDataSize(qint64 bytes, int precision, QLocale::DataSizeFormats format)
 {
     return QLocale().formattedDataSize(bytes, precision, format);
diff --git a/src/ui/util/formatutil.h b/src/ui/util/formatutil.h
index 727af1e1..c96da0ae 100644
--- a/src/ui/util/formatutil.h
+++ b/src/ui/util/formatutil.h
@@ -9,6 +9,9 @@ class FormatUtil : public QObject
     Q_OBJECT
 
 public:
+    static QString formatSize(qint64 value, int power, int precision = 2,
+            QLocale::DataSizeFormats format = QLocale::DataSizeTraditionalFormat);
+
     static QString formatDataSize(qint64 bytes, int precision = 2,
             QLocale::DataSizeFormats format = QLocale::DataSizeTraditionalFormat);