Semi-Log Graph Paper: uses, sizes and printing tips
Semi-logarithmic paper has a logarithmic vertical axis — three cycles here, each covering a power of ten — and an evenly spaced horizontal axis. Exponential growth and decay appear as straight lines, which makes it standard for bacterial growth, radioactive decay, compound interest and Bode plots.
How to print it
- Choose the paper size (US Letter, A4, Legal, A5 or Half Letter) and portrait or landscape — the page updates as you change settings.
- Set how many log cycles the vertical and horizontal axes have; a linear axis makes it semi-log paper.
- Add a title or a name/date header if you want, or keep the page plain.
- Click Print / Save as PDF. In the print dialog choose “Actual size” (100%) and turn off “Headers and footers”.
Tips
- If the data falls on a straight line, its slope gives the growth rate.
- Each cycle covers one power of ten (1–10, 10–100 …); write your own decade values next to the printed 1s.
- A straight line on semi-log paper means exponential growth or decay; on log-log paper it means a power law.
FAQ
How do I label the cycles?
Each cycle starts at a printed 1. Write your powers of ten next to them, e.g. 1, 10, 100, 1000 for three cycles.
Can I put the log scale on the horizontal axis?
Yes — set Vertical axis to Linear and Horizontal axis to the number of cycles you need (used for frequency in Bode plots).
How many cycles do I need?
Count the powers of ten in your data. Values from 2 to 900 span 1–10, 10–100 and 100–1000, so you need 3 cycles.
Is it free, and do I need an account?
It is completely free with no sign-up and no download. Change the settings, print it or save it as a PDF, and bookmark the address — your settings are stored in the link.
Related paper
More Math Graph Paper: Coordinate Plane – 4 per Page · Coordinate Plane – 6 per Page · First Quadrant Graph Paper · Blank Coordinate Plane · Polar Graph Paper · Polar Graph Paper (Radians)
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