diff --git a/src/backup/mod.rs b/src/backup/mod.rs
index f569697..cb9aa16 100644
--- a/src/backup/mod.rs
+++ b/src/backup/mod.rs
@@ -235,13 +235,8 @@ impl<T: Clone> fmt::Display for Backup<T> {
         // Pretty-print size
         // If your backup is a petabyte or larger, this will crash and you need to re-evaluate your
         // life choices
-        let mut index = 0;
-        let mut size = self.size as f64;
-
-        while size >= 1024.0 {
-            index += 1;
-            size /= 1024.0;
-        }
+        let index = self.size.ilog(1024) as usize;
+        let size = self.size as f64 / (1024.0_f64.powi(index as i32));
 
         write!(
             f,