Plan sampling points and fieldwork effort along a measured transect.
Lay out repeatable sampling points. Your results can be printed or downloaded for field use.
Enter your measurements, then calculate.
Method and assumptions
Regular positions are multiples of your interval. Including both endpoints adds the exact far endpoint when spacing does not divide length; the final gap can be shorter. Interior policy excludes both endpoints. Effort = points × replicate transects × minutes per point, excluding travel and setup. Choose random or justified starts and record direction, method, habitat and date so a survey can be repeated. Equal spacing alone does not make a sample unbiased. NPS introduction to transects.
Instructions
- Enter Transect length (m) and Point spacing (m).
- Choose Endpoint policy to include or exclude the start and far endpoint.
- Set Number of replicate transects and Observation time per point (minutes).
- Select Calculate, then use Print result or Download CSV for your field plan.
Understanding your results
A 50 m line with 5 m spacing and both endpoints included has 11 points. Three transects at two minutes per point need 66 observation minutes. Travel and setup are additional. If the interval does not divide the length, including the far endpoint creates a shorter final gap.
What to do if the number of points is different from what you expected
Check Endpoint policy. Start and end points can add observations beyond the interior regular points. Review the listed positions before laying out your line, and remember that equal spacing alone does not guarantee representative sampling.
Using this tool in your browser
This tool handles your entries in your browser with JavaScript enabled and does not save them automatically. Use the download or print controls described in the instructions to keep a copy before closing or reloading the page. On a phone, your browser controls where downloads go and which print options are available.
Summary
Use the point list as a repeatable plan and record the line direction and sampling method.