diff --git a/allanplot.m b/allanplot.m
index 85f0471..613c56a 100755
--- a/allanplot.m
+++ b/allanplot.m
@@ -7,6 +7,6 @@ mult = eval(argv(){3});
 data.freq = load(filename)(:,col).*mult;
 data.rate = 1;
 
-ad = allan(data, 2.^(0:12), strsplit(filename, '/'){end}, 1);
+ad = allan(data, 2.^(0:nextpow2(length(data.freq))), strsplit(filename, '/'){end}, 1);
 input("Press to continue...");
 exit