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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) Mixeduse 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 online CTBUH Tall Building Calculators

Office 
Residential/hotel 
Function Unkown or MixedUse^{1} 
floortofloor height (f) 
3.9m 
3.1m 
3.5m 
Entrance lobby level floortofloor 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 rooflevel mechanical areas / parapets / screen walls^{2} 
2.0f = 7.8m 
2.0f = 6.2m 
2.0f = 7.0m 
Key
H= Building height
f = Typical occupied floortofloor height
s = Total number of stories^{3}

Useable Floors 

Entrance Lobby 

Mechanical Floors 

Roof 
.asdf 
^{1}Mixeduse assumptions derived from the average values between office and residential/hotel figures.
^{2}Figures do not assume spires or other major projections at the roof plane.
^{3}The 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).
. 
1. Calculating the height of an office tall building where only the number of stories is known

Number of stories (known) = s 
Assumed floortofloor height = f = 3.9m 
Factor for increased ground level floortofloor height
Assuming the entrance lobby floortofloor 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 floortofloor height that has already been counted). 
Factor for increased mechanical levels floortofloor 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 floortofloor height = 3.9s
+ Factor for increased ground level floortofloor height = 3.9m
+ Factor for increased mechanical levels floortofloor 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
.

Number of stories (known) = s 
Assumed floortofloor height = f = 3.1m 
Factor for increased ground level floortofloor height
Assuming the entrance lobby floortofloor 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 floortofloor height that has already been counted). 
Factor for increased mechanical levels floortofloor 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 floortofloor height = 3.1s
+ Factor for increased ground level floortofloor height = 1.55m
+ Factor for increased mechanical levels floortofloor 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 mixeduse tall building or where the function of the building is unknown and the number of stories is known
.

Number of stories (known) = s 
Assumed floortofloor height = f = 3.5m 
Factor for increased ground level floortofloor height
Assuming the entrance lobby floortofloor 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 floortofloor height that has already been counted). 
Factor for increased mechanical levels floortofloor 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 floortofloor height = 3.5s
+ Factor for increased ground level floortofloor height = 2.625m
+ Factor for increased mechanical levels floortofloor 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 mixeduse or function unknown tall building: 
. 
60 MixedUse or Function Unknown Building


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: H_{office} = 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: H_{residentail} = 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% 
MixedUse or Function Unknown Buildings
CTBUH Height Calculator Formula: H_{unknown} = 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

RamatGam, 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% 
