Sounds like you might want to calculate the height of the padding based on the height of the plotting area instead of the data. But you haven't really given us enough information to give a lot of advice - for example, what plotting library you're using. Typically such styling would be the job of that library. Personally I really like Plotly.js.

I'm using gnuplot. It has an offset parameter.. but leaves me with the same problem. PS: I like Ploty.js too! But I tend to make heavy use of fenceplots https://stackoverflow.com/questions/46096494/gnuplot-alternating-colors-in-fenceplots

I'm using gnuplot. It has an offset parameter.. but leaves me with the same problem. PS: I like Ploty.js too! But I tend to make heavy use of fenceplots

I see... well perhaps the plot could be emulated with Plotly's 3D Mesh plot. But an SSCCE with Gnuplot would still be helpful to have as a basis for something to play around with.

Why not something as simple as

my $maxYaxis = $peak + 10;
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If you can only add relative paddings before scaling, then calculate it by dividing the absolute one thru the scaling factor.

$ perl -Mstrict -MPOSIX=ceil,floor -wE'
for my $peak (0.1,0.9,2.1,9.9,11,22.22,35,111,265,999,1020,120010) {
    my $base = 10**( floor(log($peak)/log(10)) - 1 );
    my $h = ceil($peak/$base) * $base;
    $h += $base if $h == $peak;  # avoid peak = max
    printf "%s\t%s\n", $peak, $h;
}
'
0.1    0.11
0.9    0.91
2.1    2.2
9.9    10
11    12
22.22    23
35    36
111    120
265    270
999    1000
1020    1100
120010    130000
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