Hand-picked intervals rarely read well
If your maximum is 4,700 and you want six ticks, the interval works out to 940. Nobody reads intermediate values off an axis like that. This tool takes the minimum, the maximum and the tick count you want, rounds the interval up to a value that reads well, and lists the axis ends along with every tick value.
How it is calculated
The data range is divided by one less than the target tick count to get a rough interval. Multiples of 1, 2 or 5 times a power of ten around that value become the candidates, and the tool keeps the one whose tick count lands closest to your target once the axis ends are snapped to the interval, preferring the smaller interval when two are equally close. The axis start is rounded down to a multiple of the interval and the end is rounded up, each once, after absorbing floating-point error. The formula and the rough interval are printed under the result, and the candidate table shows what the next larger and smaller intervals would give. Written as of October 2026.
Limits
Logarithmic axes and date or time axes are not supported. Date axes break naturally on calendar units such as 7, 12 or 30, which the 1-2-5 rule does not match. Label width and label collision are not calculated either.
Frequently asked questions
It can. The interval is restricted to the 1-2-5 family, so no candidate may land on your exact target. The tool then takes the closest one, and the smaller interval when two are equally close. You can also pick a different candidate from the table yourself.
Charts that compare quantities by bar length exaggerate differences when the axis does not start at zero. A line chart with small variation, on the other hand, hides its movement if zero is included. The tool offers both through the checkbox and does not decide for you.
Steps of 1, 2 and 5 are the ones people add up in their head. Steps of 3 or 7 make intermediate values hard to read, so they are almost never used for axis ticks.