Question 1

Why do programmers use hexadecimal instead of working in binary directly?

Accepted Answer

Because the conversion is free: every hex digit maps to exactly 4 bits (a nibble), so a byte is always exactly 2 hex digits. 0xFF is instantly 11111111 with no arithmetic required, whereas the raw binary string for a 32-bit or 64-bit value is long, error-prone to read, and easy to miscount. Hex gives the same information in a quarter of the characters, which is why memory addresses, machine code, and debuggers display values in hex rather than binary.

Question 2

How do you convert a hex number to decimal by hand?

Accepted Answer

Multiply each digit by 16 raised to its position, counting from 0 on the right, then add the results. For 0x2AF: the 2 is in the 16² place (2 × 256 = 512), A equals 10 in the 16¹ place (10 × 16 = 160), and F equals 15 in the 16⁰ place (15 × 1 = 15). Adding 512 + 160 + 15 gives 687, which is exactly what this calculator's Convert tab returns for the same input.

Question 3

What are hex color codes and how do they work?

Accepted Answer

A web color like #F97316 packs three one-byte channels — red, green, and blue — into six hex digits, two per channel (00 to FF, or 0 to 255 in decimal). #F97316 breaks down to R=249, G=115, B=22, giving an orange. Because each channel only needs two hex digits instead of three decimal digits, hex is the compact standard for CSS, design tools, and image formats. Try any code in this calculator's Color Tool tab to see its RGB breakdown.

Question 4

What's the fastest way to convert between hex and binary?

Accepted Answer

Skip decimal entirely and swap each hex digit for its 4-bit binary group, or vice versa in groups of four starting from the right. 0xA9 becomes 1010 (A) followed by 1001 (9), giving 10101001 directly — no multiplication needed. This nibble-by-nibble trick is exact because 16 is 2⁴, and it's the same method this calculator uses internally to move between the two bases.

Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex
0	00	1	01	2	02	3	03
4	04	5	05	6	06	7	07
8	08	9	09	10	0A	11	0B
12	0C	13	0D	14	0E	15	0F
16	10	17	11	18	12	19	13
20	14	21	15	22	16	23	17
24	18	25	19	26	1A	27	1B
28	1C	29	1D	30	1E	31	1F
32	20	33	21	34	22	35	23
36	24	37	25	38	26	39	27
40	28	41	29	42	2A	43	2B
44	2C	45	2D	46	2E	47	2F
48	30	49	31	50	32	51	33
52	34	53	35	54	36	55	37
56	38	57	39	58	3A	59	3B
60	3C	61	3D	62	3E	63	3F
64	40	65	41	66	42	67	43
68	44	69	45	70	46	71	47
72	48	73	49	74	4A	75	4B
76	4C	77	4D	78	4E	79	4F
80	50	81	51	82	52	83	53
84	54	85	55	86	56	87	57
88	58	89	59	90	5A	91	5B
92	5C	93	5D	94	5E	95	5F
96	60	97	61	98	62	99	63
100	64	101	65	102	66	103	67
104	68	105	69	106	6A	107	6B
108	6C	109	6D	110	6E	111	6F
112	70	113	71	114	72	115	73
116	74	117	75	118	76	119	77
120	78	121	79	122	7A	123	7B
124	7C	125	7D	126	7E	127	7F
128	80	129	81	130	82	131	83
132	84	133	85	134	86	135	87
136	88	137	89	138	8A	139	8B
140	8C	141	8D	142	8E	143	8F
144	90	145	91	146	92	147	93
148	94	149	95	150	96	151	97
152	98	153	99	154	9A	155	9B
156	9C	157	9D	158	9E	159	9F
160	A0	161	A1	162	A2	163	A3
164	A4	165	A5	166	A6	167	A7
168	A8	169	A9	170	AA	171	AB
172	AC	173	AD	174	AE	175	AF
176	B0	177	B1	178	B2	179	B3
180	B4	181	B5	182	B6	183	B7
184	B8	185	B9	186	BA	187	BB
188	BC	189	BD	190	BE	191	BF
192	C0	193	C1	194	C2	195	C3
196	C4	197	C5	198	C6	199	C7
200	C8	201	C9	202	CA	203	CB
204	CC	205	CD	206	CE	207	CF
208	D0	209	D1	210	D2	211	D3
212	D4	213	D5	214	D6	215	D7
216	D8	217	D9	218	DA	219	DB
220	DC	221	DD	222	DE	223	DF
224	E0	225	E1	226	E2	227	E3
228	E4	229	E5	230	E6	231	E7
232	E8	233	E9	234	EA	235	EB
236	EC	237	ED	238	EE	239	EF
240	F0	241	F1	242	F2	243	F3
244	F4	245	F5	246	F6	247	F7
248	F8	249	F9	250	FA	251	FB
252	FC	253	FD	254	FE	255	FF

Digit	Position	Power of 16	Value
2	2 (hundreds)	16² = 256	2 × 256 = 512
A	1 (sixteens)	16¹ = 16	10 × 16 = 160
F	0 (ones)	16⁰ = 1	15 × 1 = 15

Hex Calculator

Hexadecimal Arithmetic

Hex Reference Table (0-255)

Understanding Hexadecimal Numbers

Place Values — Example: 0x2AF

Frequently Asked Questions

Related Math Calculators

Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex
0	00	1	01	2	02	3	03
4	04	5	05	6	06	7	07
8	08	9	09	10	0A	11	0B
12	0C	13	0D	14	0E	15	0F
16	10	17	11	18	12	19	13
20	14	21	15	22	16	23	17
24	18	25	19	26	1A	27	1B
28	1C	29	1D	30	1E	31	1F
32	20	33	21	34	22	35	23
36	24	37	25	38	26	39	27
40	28	41	29	42	2A	43	2B
44	2C	45	2D	46	2E	47	2F
48	30	49	31	50	32	51	33
52	34	53	35	54	36	55	37
56	38	57	39	58	3A	59	3B
60	3C	61	3D	62	3E	63	3F
64	40	65	41	66	42	67	43
68	44	69	45	70	46	71	47
72	48	73	49	74	4A	75	4B
76	4C	77	4D	78	4E	79	4F
80	50	81	51	82	52	83	53
84	54	85	55	86	56	87	57
88	58	89	59	90	5A	91	5B
92	5C	93	5D	94	5E	95	5F
96	60	97	61	98	62	99	63
100	64	101	65	102	66	103	67
104	68	105	69	106	6A	107	6B
108	6C	109	6D	110	6E	111	6F
112	70	113	71	114	72	115	73
116	74	117	75	118	76	119	77
120	78	121	79	122	7A	123	7B
124	7C	125	7D	126	7E	127	7F
128	80	129	81	130	82	131	83
132	84	133	85	134	86	135	87
136	88	137	89	138	8A	139	8B
140	8C	141	8D	142	8E	143	8F
144	90	145	91	146	92	147	93
148	94	149	95	150	96	151	97
152	98	153	99	154	9A	155	9B
156	9C	157	9D	158	9E	159	9F
160	A0	161	A1	162	A2	163	A3
164	A4	165	A5	166	A6	167	A7
168	A8	169	A9	170	AA	171	AB
172	AC	173	AD	174	AE	175	AF
176	B0	177	B1	178	B2	179	B3
180	B4	181	B5	182	B6	183	B7
184	B8	185	B9	186	BA	187	BB
188	BC	189	BD	190	BE	191	BF
192	C0	193	C1	194	C2	195	C3
196	C4	197	C5	198	C6	199	C7
200	C8	201	C9	202	CA	203	CB
204	CC	205	CD	206	CE	207	CF
208	D0	209	D1	210	D2	211	D3
212	D4	213	D5	214	D6	215	D7
216	D8	217	D9	218	DA	219	DB
220	DC	221	DD	222	DE	223	DF
224	E0	225	E1	226	E2	227	E3
228	E4	229	E5	230	E6	231	E7
232	E8	233	E9	234	EA	235	EB
236	EC	237	ED	238	EE	239	EF
240	F0	241	F1	242	F2	243	F3
244	F4	245	F5	246	F6	247	F7
248	F8	249	F9	250	FA	251	FB
252	FC	253	FD	254	FE	255	FF

Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex
0	00	1	01	2	02	3	03
4	04	5	05	6	06	7	07
8	08	9	09	10	0A	11	0B
12	0C	13	0D	14	0E	15	0F
16	10	17	11	18	12	19	13
20	14	21	15	22	16	23	17
24	18	25	19	26	1A	27	1B
28	1C	29	1D	30	1E	31	1F
32	20	33	21	34	22	35	23
36	24	37	25	38	26	39	27
40	28	41	29	42	2A	43	2B
44	2C	45	2D	46	2E	47	2F
48	30	49	31	50	32	51	33
52	34	53	35	54	36	55	37
56	38	57	39	58	3A	59	3B
60	3C	61	3D	62	3E	63	3F
64	40	65	41	66	42	67	43
68	44	69	45	70	46	71	47
72	48	73	49	74	4A	75	4B
76	4C	77	4D	78	4E	79	4F
80	50	81	51	82	52	83	53
84	54	85	55	86	56	87	57
88	58	89	59	90	5A	91	5B
92	5C	93	5D	94	5E	95	5F
96	60	97	61	98	62	99	63
100	64	101	65	102	66	103	67
104	68	105	69	106	6A	107	6B
108	6C	109	6D	110	6E	111	6F
112	70	113	71	114	72	115	73
116	74	117	75	118	76	119	77
120	78	121	79	122	7A	123	7B
124	7C	125	7D	126	7E	127	7F
128	80	129	81	130	82	131	83
132	84	133	85	134	86	135	87
136	88	137	89	138	8A	139	8B
140	8C	141	8D	142	8E	143	8F
144	90	145	91	146	92	147	93
148	94	149	95	150	96	151	97
152	98	153	99	154	9A	155	9B
156	9C	157	9D	158	9E	159	9F
160	A0	161	A1	162	A2	163	A3
164	A4	165	A5	166	A6	167	A7
168	A8	169	A9	170	AA	171	AB
172	AC	173	AD	174	AE	175	AF
176	B0	177	B1	178	B2	179	B3
180	B4	181	B5	182	B6	183	B7
184	B8	185	B9	186	BA	187	BB
188	BC	189	BD	190	BE	191	BF
192	C0	193	C1	194	C2	195	C3
196	C4	197	C5	198	C6	199	C7
200	C8	201	C9	202	CA	203	CB
204	CC	205	CD	206	CE	207	CF
208	D0	209	D1	210	D2	211	D3
212	D4	213	D5	214	D6	215	D7
216	D8	217	D9	218	DA	219	DB
220	DC	221	DD	222	DE	223	DF
224	E0	225	E1	226	E2	227	E3
228	E4	229	E5	230	E6	231	E7
232	E8	233	E9	234	EA	235	EB
236	EC	237	ED	238	EE	239	EF
240	F0	241	F1	242	F2	243	F3
244	F4	245	F5	246	F6	247	F7
248	F8	249	F9	250	FA	251	FB
252	FC	253	FD	254	FE	255	FF

Dec	Hex	Dec	Hex	Dec	Hex	Dec	Hex
0	00	1	01	2	02	3	03
4	04	5	05	6	06	7	07
8	08	9	09	10	0A	11	0B
12	0C	13	0D	14	0E	15	0F
16	10	17	11	18	12	19	13
20	14	21	15	22	16	23	17
24	18	25	19	26	1A	27	1B
28	1C	29	1D	30	1E	31	1F
32	20	33	21	34	22	35	23
36	24	37	25	38	26	39	27
40	28	41	29	42	2A	43	2B
44	2C	45	2D	46	2E	47	2F
48	30	49	31	50	32	51	33
52	34	53	35	54	36	55	37
56	38	57	39	58	3A	59	3B
60	3C	61	3D	62	3E	63	3F
64	40	65	41	66	42	67	43
68	44	69	45	70	46	71	47
72	48	73	49	74	4A	75	4B
76	4C	77	4D	78	4E	79	4F
80	50	81	51	82	52	83	53
84	54	85	55	86	56	87	57
88	58	89	59	90	5A	91	5B
92	5C	93	5D	94	5E	95	5F
96	60	97	61	98	62	99	63
100	64	101	65	102	66	103	67
104	68	105	69	106	6A	107	6B
108	6C	109	6D	110	6E	111	6F
112	70	113	71	114	72	115	73
116	74	117	75	118	76	119	77
120	78	121	79	122	7A	123	7B
124	7C	125	7D	126	7E	127	7F
128	80	129	81	130	82	131	83
132	84	133	85	134	86	135	87
136	88	137	89	138	8A	139	8B
140	8C	141	8D	142	8E	143	8F
144	90	145	91	146	92	147	93
148	94	149	95	150	96	151	97
152	98	153	99	154	9A	155	9B
156	9C	157	9D	158	9E	159	9F
160	A0	161	A1	162	A2	163	A3
164	A4	165	A5	166	A6	167	A7
168	A8	169	A9	170	AA	171	AB
172	AC	173	AD	174	AE	175	AF
176	B0	177	B1	178	B2	179	B3
180	B4	181	B5	182	B6	183	B7
184	B8	185	B9	186	BA	187	BB
188	BC	189	BD	190	BE	191	BF
192	C0	193	C1	194	C2	195	C3
196	C4	197	C5	198	C6	199	C7
200	C8	201	C9	202	CA	203	CB
204	CC	205	CD	206	CE	207	CF
208	D0	209	D1	210	D2	211	D3
212	D4	213	D5	214	D6	215	D7
216	D8	217	D9	218	DA	219	DB
220	DC	221	DD	222	DE	223	DF
224	E0	225	E1	226	E2	227	E3
228	E4	229	E5	230	E6	231	E7
232	E8	233	E9	234	EA	235	EB
236	EC	237	ED	238	EE	239	EF
240	F0	241	F1	242	F2	243	F3
244	F4	245	F5	246	F6	247	F7
248	F8	249	F9	250	FA	251	FB
252	FC	253	FD	254	FE	255	FF