Chimney Calculator
Calculate proper chimney flue size based on appliance BTU rating. Get material estimates and code compliance information.
Appliance & Chimney Details
Appliance Type:
50,000 BTU
10,000 BTU200,000 BTU
BTU
15 ft
8 ft40 ft
Chimney Type:
Flue Shape:
8 in
4 in16 in
Required Flue Area
7.1 sq in
Recommended: 4" diameter (round)
Flue Size Adequate
Your flue: 50.3 sq in | Required: 7.1 sq in
π¨Theoretical Draft
0.75" WC
π§Flue Liner Needed
17 ft
π©Cap Size
12"
πHeight Code
Passes
Masonry Materials:
Bricks (approximate)450
Mortar Bags1
Estimated Cost:
$2,250
Based on masonry construction
Chimney Height Requirements (3-2-10 Rule)
3 Feet Minimum
Above the point where chimney passes through roof
2 Feet Higher
Than any structure within 10 feet horizontally
Draft Concerns
Taller chimneys provide better draft
π‘
Help us improve!
How would you rate the Chimney Calculator?
Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
Γ°ΕΈβΕ‘
Formula Source: Standard Mathematical References
by Various
Γ°ΕΈββLast reviewed: May 2026
Γ’ΕβFormula checks are based on standard references and internal QA review.