Axis crimes

The log scale

Every gridline is another ×10, and the eye reads them as equal steps.

a.k.a. logarithmic axis · orders of magnitude · ratio scale

A log axis spaces equal ratios equally: 1 to 10 occupies the same width as 1,000 to 10,000. For data that genuinely spans orders of magnitude that is the right tool — but the eye still reads distance as amount, so a thousandfold gap arrives on the page looking like a modest lead. Put bars on one and it gets worse: a bar encodes its value as length from zero, and a log axis has no zero, so every bar’s length is set by wherever the axis was started.

How to spot it

Read the axis numbers. 1, 10, 100, 1,000 is a log scale; 1, 2, 3 is not.
Bars on a log axis — ask where the axis begins, then imagine it beginning a decade lower.
Growth that appears to be “slowing” or “going linear”: on a log axis a straight line is a constant percentage, not a constant amount.
Two values labelled a hundredfold apart whose marks look a hand’s width apart.

The fix

If the question is how much bigger, use a linear axis from zero. Keep the log scale for ranges that genuinely span orders of magnitude, label it loudly, and give it dots rather than bars — a dot marks a position, which is all a log axis can honestly encode. If the small values deserve attention, give them their own chart at their own scale.

In the gallery

Dark navy deck slide, masthead “Format Desk · United States · full year 2025”, headlined “Streaming never did eat the format mix”. A subhead reads “Every format the industry still ships, at wholesale value for 2025. Twelve formats, none of them dropped, all of them on one shared axis — and the whole business fits inside four gridlines.” Twelve gold horizontal bars run against a logarithmic axis labelled 1, 10, 100, 1,000 and 10,000, captioned “US wholesale revenue, $ millions (log₁₀)”: Paid Subscriptions (Premium) 5,881.1, Free Streaming 1,789.3, Other Streaming 1,309.0, Vinyl 1,042.9, Paid Subscriptions (Non-Premium) 495.2, Synchronization 407.1, CD 312.4, Download Album 111.0, Download Single 110.8, Other Digital 46.7, Other Physical 25.8 and, in teal at the bottom, Ringtones & Ringbacks 4.16. Because the axis is logarithmic the bars form a gentle staircase rather than a cliff, and a teal callout beside the last one reads “$4.16 million, and still a sixth of the way across”. Three stat cards down the right side read 12 of 12 formats still earning, 6 : 1 longest bar to shortest end to end — “the entire spread of the American music business” — and $11.5B total US recorded-music revenue in 2025. A gold note box headed “The long tail is alive” argues that no single format has run away with the business and that even two million ringtones clear a sixth of the leader’s bar; under it, in small grey type, “Axis: log₁₀, bars measured from a $1M floor.” A footnote credits the RIAA Year-End 2025 Revenue Report and calls the slide a Format Desk demonstration deck.

The ringtone comeback that lived on a log axis

The log scale The truncated axis