Gallons to Cubic Inches Converter

How to convert gallons to cubic inches

cubic inches = gallons × 231

1 US gallon is exactly 231 cubic inches. 1 cubic inch is exactly 16.387064 cubic centimeters (2.54³). 1 imperial gallon is exactly 4.54609 liters.

The factor 231 is exact, not a rounded value. Nothing is rounded until you choose how many decimals to show.

Worked example: 5 gal

1. Start with the value in gallons: 5 gal.
2. Multiply by 231, because 1 gallon = 231 cubic inches: 5 × 231 = 1,155 in³.

Gallons to cubic inches chart

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Gallons from 1 to 100 converted to cubic inches with the exact factor, shown to five significant digits.

Gallons to cubic inches, part 1 of 4

gal	in³
1	231
2	462
3	693
4	924
5	1,155
6	1,386
7	1,617
8	1,848
9	2,079
10	2,310
11	2,541
12	2,772
13	3,003
14	3,234
15	3,465
16	3,696
17	3,927
18	4,158
19	4,389
20	4,620
21	4,851
22	5,082
23	5,313
24	5,544
25	5,775

Gallons to cubic inches, part 2 of 4

gal	in³
26	6,006
27	6,237
28	6,468
29	6,699
30	6,930
31	7,161
32	7,392
33	7,623
34	7,854
35	8,085
36	8,316
37	8,547
38	8,778
39	9,009
40	9,240
41	9,471
42	9,702
43	9,933
44	10,164
45	10,395
46	10,626
47	10,857
48	11,088
49	11,319
50	11,550

Gallons to cubic inches, part 3 of 4

gal	in³
51	11,781
52	12,012
53	12,243
54	12,474
55	12,705
56	12,936
57	13,167
58	13,398
59	13,629
60	13,860
61	14,091
62	14,322
63	14,553
64	14,784
65	15,015
66	15,246
67	15,477
68	15,708
69	15,939
70	16,170
71	16,401
72	16,632
73	16,863
74	17,094
75	17,325

Gallons to cubic inches, part 4 of 4

gal	in³
76	17,556
77	17,787
78	18,018
79	18,249
80	18,480
81	18,711
82	18,942
83	19,173
84	19,404
85	19,635
86	19,866
87	20,097
88	20,328
89	20,559
90	20,790
91	21,021
92	21,252
93	21,483
94	21,714
95	21,945
96	22,176
97	22,407
98	22,638
99	22,869
100	23,100

cubic inches = gallons × 231. Factors: NIST SP 811, NIST Handbook 44, UK Weights and Measures Act 1985. unitcheck.net/volume/gallons-to-cubic-inches/

US gallon or imperial gallon?

The converter starts with the US gallon (3.785411784 L, defined through the US gallon of exactly 231 cubic inches). The imperial gallon used in the United Kingdom is 4.54609 L, about 20% larger. Use the switch above the converter if your number comes from a British source.