ACI Quick Reference

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ACI 318-14 concrete properties, ASTM standard reinforcing bar dimensions, and per-foot area spacing tables for structural engineers.

Concrete Properties — ACI 318-14

f′c (psi)

wc (pcf)

Normalweight (≥ 140 pcf)

Ec §19.2.2.1

3,604,997

psi

fr §19.2.3.1

0.474

ksi

λ §19.2.4

1.00

Ec = 57,000√f′c (ACI 318-14 §19.2.2.1b, normalweight)

fr = 7.5λ√f′c (ACI 318-14 §19.2.3.1)

Bar	dia (in)	Area (in²)	Wt (lb/ft)	Std Bend — inside r		Tie Bend — inside r
Bar	dia (in)	Area (in²)	Wt (lb/ft)	in	out in	in	out in
#3	0.375	0.110	0.376	1.125	1.500	0.750	1.125
#4	0.500	0.200	0.668	1.500	2.000	1.000	1.500
#5	0.625	0.310	1.043	1.875	2.500	1.250	1.875
#6	0.750	0.440	1.502	2.250	3.000	2.250	3.000
#7	0.875	0.600	2.044	2.625	3.500	2.625	3.500
#8	1.000	0.790	2.670	3.000	4.000	3.000	4.000
#9	1.128	1.000	3.400	4.512	5.640	—	—
#10	1.270	1.270	4.303	5.080	6.350	—	—
#11	1.410	1.560	5.313	5.640	7.050	—	—
#14	1.693	2.250	7.650	8.465	10.158	—	—
#18	2.257	4.000	13.600	11.285	13.542	—	—

Target As (in²/ft)

■ insufficient■ ok (ratio < 1.5×)■ ok (ratio < 2.0×)■ excessive

s (in)	#3	#4	#5	#6	#7	#8	#9	#10	#11
4.0	0.330	0.600	0.930	1.320	1.800	2.370	3.000	3.810	4.680
4.5	0.293	0.533	0.827	1.173	1.600	2.107	2.667	3.387	4.160
5.0	0.264	0.480	0.744	1.056	1.440	1.896	2.400	3.048	3.744
5.5	0.240	0.436	0.676	0.960	1.309	1.724	2.182	2.771	3.404
6.0	0.220	0.400	0.620	0.880	1.200	1.580	2.000	2.540	3.120
6.5	0.203	0.369	0.572	0.812	1.108	1.458	1.846	2.345	2.880
7.0	0.189	0.343	0.531	0.754	1.029	1.354	1.714	2.177	2.674
7.5	0.176	0.320	0.496	0.704	0.960	1.264	1.600	2.032	2.496
8.0	0.165	0.300	0.465	0.660	0.900	1.185	1.500	1.905	2.340
8.5	0.155	0.282	0.438	0.621	0.847	1.115	1.412	1.793	2.202
9.0	0.147	0.267	0.413	0.587	0.800	1.053	1.333	1.693	2.080
9.5	0.139	0.253	0.392	0.556	0.758	0.998	1.263	1.604	1.971
10.0	0.132	0.240	0.372	0.528	0.720	0.948	1.200	1.524	1.872
10.5	0.126	0.229	0.354	0.503	0.686	0.903	1.143	1.451	1.783
11.0	0.120	0.218	0.338	0.480	0.655	0.862	1.091	1.385	1.702
11.5	0.115	0.209	0.323	0.459	0.626	0.824	1.043	1.325	1.628
12.0	0.110	0.200	0.310	0.440	0.600	0.790	1.000	1.270	1.560
12.5	0.106	0.192	0.298	0.422	0.576	0.758	0.960	1.219	1.498
13.0	0.102	0.185	0.286	0.406	0.554	0.729	0.923	1.172	1.440
13.5	0.098	0.178	0.276	0.391	0.533	0.702	0.889	1.129	1.387
14.0	0.094	0.171	0.266	0.377	0.514	0.677	0.857	1.089	1.337
14.5	0.091	0.166	0.257	0.364	0.497	0.654	0.828	1.051	1.291
15.0	0.088	0.160	0.248	0.352	0.480	0.632	0.800	1.016	1.248
15.5	0.085	0.155	0.240	0.341	0.465	0.612	0.774	0.983	1.208
16.0	0.083	0.150	0.232	0.330	0.450	0.593	0.750	0.953	1.170
16.5	0.080	0.145	0.225	0.320	0.436	0.575	0.727	0.924	1.135
17.0	0.078	0.141	0.219	0.311	0.424	0.558	0.706	0.896	1.101
17.5	0.075	0.137	0.213	0.302	0.411	0.542	0.686	0.871	1.070
18.0	0.073	0.133	0.207	0.293	0.400	0.527	0.667	0.847	1.040

As = (bar area × 12) / spacing. Click a bar header to highlight that column.