diff --git a/piker/calc.py b/piker/calc.py
index 0c891852..f5efae25 100644
--- a/piker/calc.py
+++ b/piker/calc.py
@@ -16,7 +16,7 @@ def humanize(number):
     if mag < 3:
         return number
     maxmag = max(itertools.takewhile(lambda key: mag >= key, mag2suffix))
-    return "{:.3f}{}".format(number/10**maxmag, mag2suffix[maxmag])
+    return "{:.2f}{}".format(number/10**maxmag, mag2suffix[maxmag])
 
 
 def percent_change(init, new):