Hexadecimal to Decimal Converter

Convert hexadecimal numbers to decimal (base 10) instantly. Supports 0x prefix and large numbers.

Hexadecimal Input

Decimal Output

Decimal to Hexadecimal Converter

How to Convert Hex to Decimal

Each hexadecimal digit represents a power of 16. To convert:

Identify each hex digit (0-9, A-F where A=10, F=15)
Multiply each digit by 16^position (right to left, starting at 0)
Sum all the results

Example: Convert 0xFF to decimal:

F (15) × 16¹ = 15 × 16 = 240
F (15) × 16⁰ = 15 × 1 = 15
Result: 240 + 15 = 255

Code Examples

const hex = "ff";
const decimal = parseInt(hex, 16); // 255
// For large numbers, use BigInt:
const bigHex = "ffffffffffffffff";
const bigDecimal = BigInt("0x" + bigHex);

Frequently Asked Questions

How do I convert hex to decimal?

Multiply each hex digit by its position value (16^n) and sum the results. For example, FF = (15 × 16¹) + (15 × 16⁰) = 240 + 15 = 255.

What does the 0x prefix mean?

The 0x prefix indicates a hexadecimal number in most programming languages (C, JavaScript, Python). It helps distinguish hex from decimal: 10 is ten, but 0x10 is sixteen.

Can I convert large hex numbers?

Yes! This converter supports arbitrarily large numbers using BigInt. It can handle hex values beyond the standard 64-bit integer limit.

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Conversion Table: Decimal, Hex, Binary, and Octal (0-255)

Every value one byte can hold, in all four common number bases.

Decimal	Hex	Binary	Octal
0	00	00000000	000
1	01	00000001	001
2	02	00000010	002
3	03	00000011	003
4	04	00000100	004
5	05	00000101	005
6	06	00000110	006
7	07	00000111	007
8	08	00001000	010
9	09	00001001	011
10	0A	00001010	012
11	0B	00001011	013
12	0C	00001100	014
13	0D	00001101	015
14	0E	00001110	016
15	0F	00001111	017
16	10	00010000	020
17	11	00010001	021
18	12	00010010	022
19	13	00010011	023
20	14	00010100	024
21	15	00010101	025
22	16	00010110	026
23	17	00010111	027
24	18	00011000	030
25	19	00011001	031
26	1A	00011010	032
27	1B	00011011	033
28	1C	00011100	034
29	1D	00011101	035
30	1E	00011110	036
31	1F	00011111	037
32	20	00100000	040
33	21	00100001	041
34	22	00100010	042
35	23	00100011	043
36	24	00100100	044
37	25	00100101	045
38	26	00100110	046
39	27	00100111	047
40	28	00101000	050
41	29	00101001	051
42	2A	00101010	052
43	2B	00101011	053
44	2C	00101100	054
45	2D	00101101	055
46	2E	00101110	056
47	2F	00101111	057
48	30	00110000	060
49	31	00110001	061
50	32	00110010	062
51	33	00110011	063
52	34	00110100	064
53	35	00110101	065
54	36	00110110	066
55	37	00110111	067
56	38	00111000	070
57	39	00111001	071
58	3A	00111010	072
59	3B	00111011	073
60	3C	00111100	074
61	3D	00111101	075
62	3E	00111110	076
63	3F	00111111	077
64	40	01000000	100
65	41	01000001	101
66	42	01000010	102
67	43	01000011	103
68	44	01000100	104
69	45	01000101	105
70	46	01000110	106
71	47	01000111	107
72	48	01001000	110
73	49	01001001	111
74	4A	01001010	112
75	4B	01001011	113
76	4C	01001100	114
77	4D	01001101	115
78	4E	01001110	116
79	4F	01001111	117
80	50	01010000	120
81	51	01010001	121
82	52	01010010	122
83	53	01010011	123
84	54	01010100	124
85	55	01010101	125
86	56	01010110	126
87	57	01010111	127
88	58	01011000	130
89	59	01011001	131
90	5A	01011010	132
91	5B	01011011	133
92	5C	01011100	134
93	5D	01011101	135
94	5E	01011110	136
95	5F	01011111	137
96	60	01100000	140
97	61	01100001	141
98	62	01100010	142
99	63	01100011	143
100	64	01100100	144
101	65	01100101	145
102	66	01100110	146
103	67	01100111	147
104	68	01101000	150
105	69	01101001	151
106	6A	01101010	152
107	6B	01101011	153
108	6C	01101100	154
109	6D	01101101	155
110	6E	01101110	156
111	6F	01101111	157
112	70	01110000	160
113	71	01110001	161
114	72	01110010	162
115	73	01110011	163
116	74	01110100	164
117	75	01110101	165
118	76	01110110	166
119	77	01110111	167
120	78	01111000	170
121	79	01111001	171
122	7A	01111010	172
123	7B	01111011	173
124	7C	01111100	174
125	7D	01111101	175
126	7E	01111110	176
127	7F	01111111	177
128	80	10000000	200
129	81	10000001	201
130	82	10000010	202
131	83	10000011	203
132	84	10000100	204
133	85	10000101	205
134	86	10000110	206
135	87	10000111	207
136	88	10001000	210
137	89	10001001	211
138	8A	10001010	212
139	8B	10001011	213
140	8C	10001100	214
141	8D	10001101	215
142	8E	10001110	216
143	8F	10001111	217
144	90	10010000	220
145	91	10010001	221
146	92	10010010	222
147	93	10010011	223
148	94	10010100	224
149	95	10010101	225
150	96	10010110	226
151	97	10010111	227
152	98	10011000	230
153	99	10011001	231
154	9A	10011010	232
155	9B	10011011	233
156	9C	10011100	234
157	9D	10011101	235
158	9E	10011110	236
159	9F	10011111	237
160	A0	10100000	240
161	A1	10100001	241
162	A2	10100010	242
163	A3	10100011	243
164	A4	10100100	244
165	A5	10100101	245
166	A6	10100110	246
167	A7	10100111	247
168	A8	10101000	250
169	A9	10101001	251
170	AA	10101010	252
171	AB	10101011	253
172	AC	10101100	254
173	AD	10101101	255
174	AE	10101110	256
175	AF	10101111	257
176	B0	10110000	260
177	B1	10110001	261
178	B2	10110010	262
179	B3	10110011	263
180	B4	10110100	264
181	B5	10110101	265
182	B6	10110110	266
183	B7	10110111	267
184	B8	10111000	270
185	B9	10111001	271
186	BA	10111010	272
187	BB	10111011	273
188	BC	10111100	274
189	BD	10111101	275
190	BE	10111110	276
191	BF	10111111	277
192	C0	11000000	300
193	C1	11000001	301
194	C2	11000010	302
195	C3	11000011	303
196	C4	11000100	304
197	C5	11000101	305
198	C6	11000110	306
199	C7	11000111	307
200	C8	11001000	310
201	C9	11001001	311
202	CA	11001010	312
203	CB	11001011	313
204	CC	11001100	314
205	CD	11001101	315
206	CE	11001110	316
207	CF	11001111	317
208	D0	11010000	320
209	D1	11010001	321
210	D2	11010010	322
211	D3	11010011	323
212	D4	11010100	324
213	D5	11010101	325
214	D6	11010110	326
215	D7	11010111	327
216	D8	11011000	330
217	D9	11011001	331
218	DA	11011010	332
219	DB	11011011	333
220	DC	11011100	334
221	DD	11011101	335
222	DE	11011110	336
223	DF	11011111	337
224	E0	11100000	340
225	E1	11100001	341
226	E2	11100010	342
227	E3	11100011	343
228	E4	11100100	344
229	E5	11100101	345
230	E6	11100110	346
231	E7	11100111	347
232	E8	11101000	350
233	E9	11101001	351
234	EA	11101010	352
235	EB	11101011	353
236	EC	11101100	354
237	ED	11101101	355
238	EE	11101110	356
239	EF	11101111	357
240	F0	11110000	360
241	F1	11110001	361
242	F2	11110010	362
243	F3	11110011	363
244	F4	11110100	364
245	F5	11110101	365
246	F6	11110110	366
247	F7	11110111	367
248	F8	11111000	370
249	F9	11111001	371
250	FA	11111010	372
251	FB	11111011	373
252	FC	11111100	374
253	FD	11111101	375
254	FE	11111110	376
255	FF	11111111	377

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Want to learn the method behind this tool? Read How to Convert Hexadecimal to Decimal - the full step-by-step guide.

Hexadecimal to Decimal Converter

How to Convert Hex to Decimal

Code Examples

Frequently Asked Questions

How do I convert hex to decimal?

What does the 0x prefix mean?

Can I convert large hex numbers?

Related Tools

Decimal to Hexadecimal Converter

Hexadecimal to Binary Converter

Universal Base Converter & Number Inspector

Conversion Table: Decimal, Hex, Binary, and Octal (0-255)

Popular hexadecimal to decimal conversions