Council on Tall Buildings and Urban Habitat
 

Height Calculator

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The CTBUH has developed this tall building height calculator to assist in determining tall building heights when only the story count is known. The calculator is divided into three categories representing the three major functions represented in tall buildings;
             (i) Office
             (ii) Residential/Hotel
             (iii) Mixed-use or when the function unknown

The calculator will provide an approximate height for a single tall building, but as tall building characteristics vary significantly with location, structural material, form, profile, etc, in some instances estimates will vary considerably with actual building height. As such, the calculator is best utilized to determine heights in multiple building / statistical studies, where there are many unknown building heights. In these instances the greater number of buildings examined will reduce any overall variations.

The calculator does not include any factors for spires or any other major projections at the roof plane, due to the wide ranging nature of these.

The height calculator is never utilized by the CTBUH to determine any building heights as part of the CTBUH tall building database i.e. all published heights within the CTBUH database are accurate, confirmed heights according to published data.


Click here to utilize the on-line CTBUH Tall Building Calculators



Height Calculator Assumptions

Office Residential/hotel Function Unkown or Mixed-Use1
floor-to-floor height (f) 3.9m 3.1m 3.5m
Entrance lobby level floor-to-floor height 2.0f = 7.8m 1.5f = 4.65m 1.75f = 6.125m
Number of mechanical floors above ground (excluding those on the roof) s/20 = One mechanical floor every 20 stories s/30 = One mechanical floor every 30 stories s/25 = One mechanical floor every 25 stories
Height of mechanical floors 2.0f = 7.8m 1.5f = 4.65m 1.75f = 6.125m
Height of roof-level mechanical areas / parapets / screen walls2 2.0f = 7.8m 2.0f = 6.2m 2.0f = 7.0m
Key

H= Building height
f = Typical occupied floor-to-floor height
s = Total number of stories3
        
 
Useable Floors
Entrance Lobby
Mechanical Floors
Roof
 
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1Mixed-use assumptions derived from the average values between office and residential/hotel figures.

2Figures do not assume spires or other major projections at the roof plane.

3The number of stories should include the ground floor level and be the number of main floors above ground, including any significant mezzanine floors and major mechanical plant floors. Mechanical mezzanines or penthouses should not be included if they have a significantly smaller floor area than the major floors below. CTBUH floor counts may differ from published accounts, as it is common in some regions of the world for certain floor levels not to be included (for example, the level 4, 14, 24, etc in Hong Kong).

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1. Calculating the height of an office tall building where only the number of stories is known

Number of stories (known) = s
Assumed floor-to-floor height = f = 3.9m
Factor for increased ground level floor-to-floor height
Assuming the entrance lobby floor-to-floor height is 7.8m, the factor will be an additional 7.8 minus (–) 3.9 = 3.9m
(e.g. discounting the 3.9m of the ground level floor-to-floor height that has already been counted).
Factor for increased mechanical levels floor-to-floor height
Assuming the mechanical levels are 7.8m high, the factor will be an additional 7.8 minus (–) 3.9 = 3.9m per mechanical floor
(e.g. discounting the 3.9m of the mechanical floors that have already been counted). The number of mechanical floors is calculated by the total number of floors divided by 20 = s/20
Factor for roof level mechanical systems / parapets / roof features
Assume this is an additional 7.8m in height (there is no need to discount any stories as roof level mechanical systems / parapets / roof features are not included in the figure for total story count).

Height of building = number of stories x floor-to-floor height = 3.9s
+ Factor for increased ground level floor-to-floor height = 3.9m
+ Factor for increased mechanical levels floor-to-floor height = 3.9m x (s/20)
+ Factor for roof level mechanical systems / parapets / roof features = 7.8m
Final formula for calculating the height of an office tall building:

.
60 Story Office Building


2. Calculating the height of a residential/hotel tall building where only the number of stories is known

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Number of stories (known) = s
Assumed floor-to-floor height = f = 3.1m
Factor for increased ground level floor-to-floor height
Assuming the entrance lobby floor-to-floor height is 4.65m, the factor will be an additional 4.65 minus (–) 3.1 = 1.55m
(e.g. discounting the 3.1m of the ground level floor-to-floor height that has already been counted).
Factor for increased mechanical levels floor-to-floor height
Assuming the mechanical levels are 4.65m high, the factor will be an additional 4.65 minus (–) 3.1 = 1.55m per mechanical floor
(e.g. discounting the 3.1m of the mechanical floors that have already been counted). The number of mechanical floors is calculated by the total number of floors divided by 30 = s/30.
Factor for roof level mechanical systems / parapets / roof features
Assume this is an additional 6.2m in height (there is no need to discount any stories as roof level mechanical systems / parapets / roof features are not included in the figure for total story count).

Height of building = number of stories x floor-to-floor height = 3.1s
+ Factor for increased ground level floor-to-floor height = 1.55m
+ Factor for increased mechanical levels floor-to-floor height = 1.55m x (s/30)
+ Factor for roof level mechanical systems / parapets / roof features = 6.2m
Final formula for calculating the height of a residential/hotel building:

.
60 Story Residential/Hotel Building


3. Calculating the height of a mixed-use tall building or where the function of the building is unknown and the number of stories is known

.

Number of stories (known) = s
Assumed floor-to-floor height = f = 3.5m
Factor for increased ground level floor-to-floor height
Assuming the entrance lobby floor-to-floor height is  6.125m, the factor will be an additional  6.125 minus (–) 3.5 = 2.625m
(e.g. discounting the 3.5m of the ground level floor-to-floor height that has already been counted).
Factor for increased mechanical levels floor-to-floor height
Assuming the mechanical levels are  6.125m high, the factor will be an additional 6.125 minus (–) 3.5 = 2.625m per mechanical floor
(e.g. discounting the 3.5m of the mechanical floors that have already been counted). The number of mechanical floors is calculated by the total number of floors divided by 25 = s/25.
Factor for roof level mechanical systems / parapets / roof features
Assume this is an additional 7.0m in height (there is no need to discount any stories as roof level mechanical systems / parapets / roof features are not included in the figure for total story count).

Height of building = number of stories x floor-to-floor height = 3.5s
+ Factor for increased ground level floor-to-floor height = 2.625m
+ Factor for increased mechanical levels floor-to-floor height = 2.625m x (s/25)
+ Factor for roof level mechanical systems / parapets / roof features = 7.0m
Final formula for calculating the height of a mixed-use or function unknown tall building:

.
60 Mixed-Use or Function Unknown Building



Height Calculator Examples and Verification

Note: To validate the CTBUH Tall Building Height Calculator, the actual height of 15 buildings in each of the three categories has been compared to the height as determined by the height calculator. The estimated and actual heights are presented with the Aggregated variance.

Asia North America Middle East
South America
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Europe Central America Australasia Africa
Office Buildings
CTBUH Height Calculator Formula: Hoffice = 3.9s + 11.7 + 3.9(s/20)
Name Location Year Completed Story Count Known building
height (m)
CTBUH height calculator figure (m) % Variation
GE Building New York, NY 1933 70 259 298 15.19%
BP Centre Cape Town, South Africa 1972  32 126 143 13.29%
Sears Tower Chicago, IL 1974 110 442 462 4.56%
First Canadian Place Toronto, Canada 1975 72 298 307 2.87%
Rialto Tower Melbourne, AUS 1986 63 251 270  7.44%
OUB Centre Singapore 1986 66 280 282 0.70%
ASEM Tower Seoul, South Korea 1992 42 176 184 4.37%
DG Bank Frankfurt, Germany 1993 53 208 229 9.97%
BOCOM Financial Towers Shanghai, China 2001 50 230 216 -5.89%
40 Bank St. London, UK 2003 33 153 147 -4.03%
AZIA Center Shanghai, China 2006 36 168 159 -5.29%
Hearst Headquarters New York, NY 2007 46 182 200 10.13%
Torre YPF Buenos Aires, Argentina 2009 36 160 159 -0.55%
Breeze Tower Osaka, Japan 2009 34 175 151 -13.75%
Manitoba Hydro Place Winnipeg, Canada 2009 22 115 102 -11.49%
Aggregated variance: 1.82%
Residentail/Hotel Buildings
CTBUH Height Calculator Formula: Hresidentail = 3.1s + 7.75 + 1.55(s/30)
Name Location Year Completed Story Count Known building
height (m)
CTBUH height calculator figure (m) % Variation
Marina City Towers Chicago, IL 1964 61 179 200 11.73%
Park Inn Berlin Berlin, Germany 1970 41 125 137 9.57%
Residencias Tajamar Caracas, Venezuela 1972 44 120 146 22.02%
Residencial del Bosque I Mexico City, Mexico 1997 30 110 102 -7.00%
Baiyoke Sky Hotel
Bangkok, Thailand
1999 88 309 285 -7.74%
Sorrento 1
Hong Kong
2003 75 256 244 -4.64%
World Tower
Sydney, Australia
2004 73 230 238 3.40%
Tehran International Tower
Tehran, Iran
2007 54 162 178 9.84%
Beetham Tower
Manchester, UK
2007 50 169 165  -2.26%
Eureka Tower Melbourne, Australia 2007 91 297 295 -0.88%
Het Strijkijzer
Hague, Netherlands
2007 42 132 140 6.15%
Saigon Pearl Tower
Ho Chi Min City, Vietnam
2007 38 135 128 -5.55%
Shaiba Tower 1
 Dubai, UAE
2007 34 155 115 -25.87%
Marquis Miami, FL 2009 63 207 206 -0.32%
301 Mission San Francisco, CA 2009 58 197 191 -3.08%
Aggregated variance: 0.36%
Mixed-Use or Function Unknown Buildings
CTBUH Height Calculator Formula: Hunknown = 3.5s + 9.625 + 2.265(s/25)
Name Location Year Completed Story Count Known building
height (m)
CTBUH height calculator figure (m) % Variation
Torre Velasca Milan, Italy 1958 26 106 103 -2.50%
John Hancock Center
Chicago, IL
1969 95 343 352 2.65%
Torre Costa Rica A Coruna, Spain 1975 31 119 121 2.00%
Trump Tower New York, NY 1982 58 202 219 8.27%
The Peak Makati, Philippines 1991 38 138 147 6.24%
Fujairah Tower Fujairah, UAE 1992 47 155 179 15.52%
Rinku Gate Tower Izumisano, Japan 1996 56 256 212 -17.38%
Tuntux Sky Tower
 Kaohsiung, Taiwan
1998 85 348 316 -9.18%
Millenium Tower Rotterdam, Netherlands 2000 34 149 132 -11.28%
Hundai 41 Tower Seoul, South Korea 2001 41 168 157 -6.29%
City Gate Tower
Ramat-Gam, Isreal
2007 68 244 255  4.41%
Naberezhnaya Tower C
Moscow, Russia
2007 61 268 230  -14.35%
SYV Tower
Madrid, Spain
2008 52 236 197 -16.49%
China World Trade Center Tower III Beijing, China 2009 74 330 276 -16.24%
Nile City
Cairo, Egypt
2009 36 143 139 -2.51%
Aggregated variance: -3.81%