Visual measurement guide
How to Measure DBH on Real-World Trees
The basic calculation is simple. Slopes, leaning trunks, forks and bulges are where a preliminary homeowner measurement needs extra care.
Edge cases
Where should the tape go?
Tree on a slope
Start the 1.4 m height from the uphill side. Keep the circumference tape level around the trunk.
Leaning tree
Measure the height along the stem and take the circumference perpendicular to the stem—not as a horizontal loop in the air.
Bulge or branch at 1.4 m
Take a preliminary measurement just above or below the irregularity where the trunk returns to normal form. Record the alternate height.
Fork near 1.4 m
Measure below the swelling if the fork distorts the normal trunk at breast height, then photograph and record where you measured.
Multi-stem trees
Do not invent a single London formula
Urban-forestry protocols differ. Some measure separate stems and combine their cross-sectional areas; others measure below the fork or use the largest stem for a particular regulatory purpose.
London’s public TCCP page defines the standard 1.4 m measurement but does not publish a special multi-stem formula. For a tree near the 40 cm grant threshold or 50 cm by-law threshold, send photographs and measurements to City Forestry or ask a qualified arborist before treating the result as definitive.
Possible TCCP size fit
Size alone does not approve funding. Work type, ownership, timing, professional qualifications and City review still matter.
Possible Distinctive Tree
Within London’s Urban Growth Boundary, a private tree at this size may fall under the Distinctive Tree rules. Tree Protection Areas use different rules.
Primary sources
Check the official rules
Program decisions are made by the City of London. These sources were reviewed on July 29, 2026.