Outdoor map tool
Garden Sunlight Hours and Shade Calculator
A plant label’s ‘full sun’ recommendation is useful only when you know how many hours reach the actual bed. SunCarta samples the day at the selected point and subtracts the periods blocked by the obstacles you add.
- Cost
- Free
- Account
- Not required
- Project data
- Browser-local
Loading the global map…
Click once to move the receiving point.
What this tool calculates
- Estimated direct-sun duration in ten-minute samples
- Seasonal changes in sunrise, sunset and solar arc
- Shade cast by measured buildings and walls
- An adjustable approximation for tree-crown density
How to use it
- 01
Pin one growing spot
Place the point inside the bed rather than using the garden’s street address as a substitute.
- 02
Draw the skyline
Add the nearest structures and mature trees first; distant low obstacles usually matter less.
- 03
Compare seasons
Check dates near midsummer, the equinoxes and midwinter. Record the result before moving the active point to a different bed.
How to read the result
Direct-sun hours
The total counts sampled intervals during which the sun is above the horizon and no modeled obstacle blocks the outdoor point. A garden point is not limited by a window-facing direction.
Plant labels
Treat six-plus hours, three-to-six hours and under three hours as broad gardening conventions, not guarantees for every species or climate.
Limits you should know
- Foliage changes by species, pruning and season.
- Small gaps between leaves and reflected light are not resolved.
- Slope, fences with gaps and pergolas need simplified obstacle shapes.
Questions about this calculator
Which date should I use for a vegetable garden?
Test the beginning, middle and end of the crop’s growing season. A single midsummer date can overstate spring or autumn exposure.
Can I test several garden beds?
Yes. Record the result for the current bed, then move the active point and repeat with the same dates and obstacle assumptions. The current release stores one active setup rather than a side-by-side report.
Methodology version 1.1 · Reviewed August 8, 2026