We use a highly accurate spreadsheet for calculating surface areas of our product. We would like to share this technology with our customers to help you more accurately calculate the cost and weight of your finished product.

For cost and weight estimating most producers simply guesstimate by determining the volume of a round flat hole. In the example below you can see how inaccurate this can be.

EXAMPLE:  62" Diameter hole in a 6 ft. manhole

Calculated as a flat hole it displaces .454 3 yds.

Actual displacement  .545 3 yds.

This represents a 20% error in a single hole.

Whether you use this information to determine the weight of your finished product, the net cost of materials or to calculate just much your coring operation is costing you, we sincerely hope this accomplishes its purpose.
VOLUME ESTIMATOR FOR HOLES IN CONCRETE MANHOLES
STRUCTURE SIZE 48X5 60X6 72X7 84X8 96X9 120X11
HOLE DIA. CUBIC YARDS CUBIC YARDS CUBIC YARDS CUBIC YARDS CUBIC YARDS CUBIC YARDS
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
52
54
58
62
64
72
78
88
 0.005412
0.008479
0.012250
0.016741
0.021967
0.027955
0.034727
0.042318
0.050769
0.060128
0.070456
0.081829
0.094342
0.108123
0.123345
0.140250
0.159198
0.180788
0.206147
0.238088
0.304618








 0.006484
0.010148
0.014644
0.019981
0.026173
0.033237
0.041190
0.050053
0.059852
0.070619
0.082386
0.095193
0.109090
0.124133
0.140390
0.157942
0.176890
0.197360
0.219507
0.243540
0.269739
0.330406
0.386525






 0.007557227
0.011821202
0.017048397
0.023243313
0.030419453
0.038588820
0.047763417
0.057959748
0.069198817
0.081498628
0.094887689
0.109390003
0.125038580
0.141869427
0.159924554
0.179248971
0.199899691
0.221936728
0.245435099
0.270481824
0.297177426
0.356037380
0.388539309
0.460893347
0.545722737
0.594528892



 0.008632
0.013500
0.019460
0.026519
0.034688
0.043975
0.054391
0.065950
0.078666
0.092557
0.107642
0.123940
0.141476
0.160278
0.180372
0.201795
0.224580
0.248771
0.274414
0.301560
0.330273
0.392668
0.426519
0.500057
0.582303
0.627154
0.838675
1.050490

 0.009707
0.015177
0.021873
0.029801
0.038966
0.049379
0.061049
0.073985
0.088202
0.103711
0.120530
0.138677
0.158167
0.179024
0.201269
0.224931
0.250033
0.276611
0.304695
0.334325
0.365540
0.432926
0.469201
0.547243
0.633135
0.679261
0.888088
1.075957
1.484255
 0.011859
0.018538
0.026710
0.036377
0.047545
0.060222
0.074416
0.090252
0.107383
0.126176
0.146525
0.168442
0.191939
0.217032
0.243737
0.272072
0.302054
0.333709
0.367056
0.402117
0.438920
0.517870
0.560079
0.650145
0.748015
0.799994
1.029529
1.226391
1.609721
VOLUME ESTIMATOR FOR HOLES IN CONCRETE INLETS OR CATCH BASINS
STRUCTURE SIZE 6" FLAT/STRAIGHT WALL 8" FLAT/STRAIGHT WALL
HOLE DIA. CUBIC YARDS CUBIC YARDS
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
52
54
58
62
64
72
 0.006465
0.010100
0.014545
0.019797
0.025856
0.032725
0.040401
0.048885
0.058178
0.068278
0.079186
0.090903
0.103427
0.116759
0.130900
0.145847
0.161605
0.178169
0.195541
0.213722
0.232711
0.273112
0.305534
0.339774
0.388255
0.413708
0.523598
 0.008620
0.013467
0.019393
0.026396
0.034630
0.043633
0.053868
0.065180
0.077570
0.091037
0.105581
0.121204
0.137903
0.155679
0.174534
0.194463
0.215473
0.237558
0.260722
0.284962
0.310281
0.364150
0.392699
0.453032
0.517673
0.551610
0.698131
PIPE O.D CHART
Hole forms are identified as face diameters in inches.
Not Individual Pipe Application

PIPE PIPE O.D. PIPE PIPE O.D.
12" RCP B-Wall
12" RCP C-Wall
12" Corrugated Steel
12" DIP
12" PVC SDR35
12" Corr. HDPE
12" VCP
15" RCP B-Wall
15" RCP C-Wall
15" Corrugated Steel
15" PVC SDR35
15" Corr. HDPE
15" VCP
18" RCP B-Wall
18" RCP C-Wall
18" Corrugated Steel
18" DIP
18" PVC SDR35
18" Corr. HDPE
18" VCP
21" RCP B-Wall
21" RCP C-Wall
21" Corrugated Steel
21" PVC SDR35
21" Corr. HDPE
21" VCP
24" RCP B-Wall
24" RCP C-Wall
24" Corrugated Steel
24" DIP
24" PVC SDR35
24" Corr. HDPE
24" VCP
27" RCP B-Wall
27" RCP C-Wall
27" Corrugated Steel
27" PVC SDR35
 		16.00"
17.50"
13.00"
13.20"
12.50"
14.00"
14.25"
19.50"
21.00"
16.00"
15.30"
18.00"
17.75"
23.00"
24.50"
19.00"
19.50"
18.70"
21.00"
20.75"
26.50"
28.00"
22.00"
22.05"
24.00"
26.00"
30.00"
31.50"
25.00"
25.80"
24.80"
27.00"
28.50"
33.50"
35.00"
28.00"
27.95"
 30" RCP B-Wall
30" RCP C-Wall
30" Corrugated Steel
30" DIP
30" PVC SDR35
30" Corr. HDPE
30" VCP
33" RCP B-Wall
33" RCP C-Wall
33" Corrugated Steel
36" RCP B-Wall
36" RCP C-Wall
36" Corrugated Steel
36" DIP
36" PVC SDR35
36" Corr. HDPE
42" RCP B-Wall
42" RCP C-Wall
42" Corrugated Steel
42" DIP
42" Corr. HDPE
48" RCP B-Wall
48" RCP C-Wall
48" Corrugated Steel
48" DIP
48" PVC SDR35
48" Corr. HDPE
54" RCP B-Wall
54" RCP C-Wall
54" Corrugated Steel
54" DIP
54" Corr. HDPE
60" RCP B-Wall
60" RCP C-Wall
60" Corrugated Steel
60" DIP
60" Corr. HDPE
66" RCP B-Wall
66" RCP C-Wall
66" Corrugated Steel
72" RCP B-Wall
72" RCP C-Wall
72" Corrugated Steel
72" Corr. HDPE
78" RCP B-Wall
78" RCP C-Wall
84" RCP B-Wall
84" RCP C-Wall
90" RCP B-Wall
90" RCP C-Wall
96" RCP B-Wall
96" RCP C-Wall
 37.00"
38.50"
31.00"
32.00"
31.50"
34.00"
36.00"
40.50"
42.00"
34.00"
44.00"
45.50"
37.00"
38.30"
39.00"
41.00"
51.00"
52.50"
43.00"
44.50"
48.00"
58.00"
59.50"
49.00"
50.80"
50.50"
54.00"
65.00"
66.50"
55.00"
57.10"
61.00"
72.00"
73.50"
62.00"
61.50"
67.00"
79.00"
80.50"
68.00"
86.00"
87.50"
74.00"
80.00"
93.00"
94.50"
100.00"
101.50"
107.00"
108.50"
114.00"
115.50"
NOTE: This information is to be used as a reference guide only. Pipe O.D.'s can vary slightly from manufacturer to manufacturer. If in doubt, please verify pipe O.D. with the supplier to the specific job.
USE AND CARE GUIDE
 

National Precast Concrete Association

1900 Ray Davis Boulevard - Seminole, OK - (405)382-7700 - Fax (405)382-7770

Toll Free: (800)876-2474 - email: Sales at Formcrete