WormFood's AVR Baud Rate Calculator

Bit Rate	UBRR	UBRR (hex)	% of error
32.768 Khz
300	13	0x000D	2.5
600	6	0x0006	2.5
1200	2	0x0002	12.1
2400	1	0x0001	17.2
4800	0	0x0000	17.2
9600	0	0x0000	134.4
14400	0	0x0000	251.6
19200	0	0x0000	368.8
28800	0	0x0000	603.1
38400	0	0x0000	837.5
57600	0	0x0000	1306.2
76800	0	0x0000	1775.0
115200	0	0x0000	2712.5
230400	0	0x0000	5525.0

Bit Rate	UBRR	UBRR (hex)	% of error
1.8432 Mhz
300	767	0x02FF	0.0
600	383	0x017F	0.0
1200	191	0x00BF	0.0
2400	95	0x005F	0.0
4800	47	0x002F	0.0
9600	23	0x0017	0.0
14400	15	0x000F	0.0
19200	11	0x000B	0.0
28800	7	0x0007	0.0
38400	5	0x0005	0.0
57600	3	0x0003	0.0
76800	2	0x0002	0.0
115200	1	0x0001	0.0
230400	0	0x0000	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
2.4576 Mhz
300	1023	0x03FF	0.0
600	511	0x01FF	0.0
1200	255	0x00FF	0.0
2400	127	0x007F	0.0
4800	63	0x003F	0.0
9600	31	0x001F	0.0
14400	20	0x0014	1.6
19200	15	0x000F	0.0
28800	10	0x000A	3.1
38400	7	0x0007	0.0
57600	4	0x0004	6.2
76800	3	0x0003	0.0
115200	2	0x0002	12.5
230400	0	0x0000	25.0

Bit Rate	UBRR	UBRR (hex)	% of error
3.072 Mhz
300	1279	0x04FF	0.0
600	639	0x027F	0.0
1200	319	0x013F	0.0
2400	159	0x009F	0.0
4800	79	0x004F	0.0
9600	39	0x0027	0.0
14400	26	0x001A	1.2
19200	19	0x0013	0.0
28800	12	0x000C	2.5
38400	9	0x0009	0.0
57600	6	0x0006	5.0
76800	4	0x0004	0.0
115200	2	0x0002	10.0
230400	1	0x0001	20.0

Bit Rate	UBRR	UBRR (hex)	% of error
3.2768 Mhz
300	1364	0x0554	0.0
600	682	0x02AA	0.0
1200	340	0x0154	0.1
2400	170	0x00AA	0.2
4800	84	0x0054	0.4
9600	42	0x002A	0.8
14400	27	0x001B	1.6
19200	20	0x0014	1.6
28800	13	0x000D	1.6
38400	10	0x000A	3.1
57600	6	0x0006	1.6
76800	4	0x0004	6.2
115200	3	0x0003	12.5
230400	1	0x0001	12.5

Bit Rate	UBRR	UBRR (hex)	% of error
3.579545 Mhz
300	1490	0x05D2	0.0
600	745	0x02E9	0.0
1200	372	0x0174	0.0
2400	185	0x00B9	0.2
4800	92	0x005C	0.2
9600	46	0x002E	0.8
14400	30	0x001E	0.2
19200	22	0x0016	1.3
28800	15	0x000F	3.0
38400	11	0x000B	3.0
57600	7	0x0007	3.0
76800	5	0x0005	3.0
115200	3	0x0003	3.0
230400	1	0x0001	3.0

Bit Rate	UBRR	UBRR (hex)	% of error
3.6864 Mhz
300	1535	0x05FF	0.0
600	767	0x02FF	0.0
1200	383	0x017F	0.0
2400	191	0x00BF	0.0
4800	95	0x005F	0.0
9600	47	0x002F	0.0
14400	31	0x001F	0.0
19200	23	0x0017	0.0
28800	15	0x000F	0.0
38400	11	0x000B	0.0
57600	7	0x0007	0.0
76800	5	0x0005	0.0
115200	3	0x0003	0.0
230400	1	0x0001	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
3.93216 Mhz
300	1637	0x0665	0.0
600	818	0x0332	0.0
1200	409	0x0199	0.1
2400	204	0x00CC	0.1
4800	101	0x0065	0.4
9600	50	0x0032	0.4
14400	33	0x0021	0.4
19200	25	0x0019	1.6
28800	16	0x0010	0.4
38400	12	0x000C	1.6
57600	8	0x0008	5.5
76800	5	0x0005	6.2
115200	3	0x0003	6.2
230400	1	0x0001	6.2

Bit Rate	UBRR	UBRR (hex)	% of error
4 Mhz
300	1666	0x0682	0.0
600	832	0x0340	0.0
1200	416	0x01A0	0.1
2400	207	0x00CF	0.2
4800	103	0x0067	0.2
9600	51	0x0033	0.2
14400	34	0x0022	0.8
19200	25	0x0019	0.2
28800	16	0x0010	2.1
38400	12	0x000C	0.2
57600	8	0x0008	3.7
76800	6	0x0006	7.5
115200	3	0x0003	7.8
230400	1	0x0001	7.8

Bit Rate	UBRR	UBRR (hex)	% of error
4.194304 Mhz
300	1747	0x06D3	0.0
600	873	0x0369	0.0
1200	436	0x01B4	0.0
2400	217	0x00D9	0.2
4800	108	0x006C	0.2
9600	54	0x0036	0.7
14400	35	0x0023	1.1
19200	26	0x001A	1.1
28800	17	0x0011	1.1
38400	13	0x000D	2.5
57600	8	0x0008	1.1
76800	6	0x0006	2.5
115200	4	0x0004	9.9
230400	1	0x0001	12.1

Bit Rate	UBRR	UBRR (hex)	% of error
4.433619 Mhz
300	1846	0x0736	0.0
600	923	0x039B	0.0
1200	461	0x01CD	0.0
2400	230	0x00E6	0.0
4800	114	0x0072	0.4
9600	57	0x0039	0.5
14400	37	0x0025	1.3
19200	28	0x001C	0.5
28800	18	0x0012	1.3
38400	13	0x000D	3.0
57600	9	0x0009	3.9
76800	6	0x0006	3.0
115200	4	0x0004	3.9
230400	1	0x0001	16.9

Bit Rate	UBRR	UBRR (hex)	% of error
4.608 Mhz
300	1919	0x077F	0.0
600	959	0x03BF	0.0
1200	479	0x01DF	0.0
2400	239	0x00EF	0.0
4800	119	0x0077	0.0
9600	59	0x003B	0.0
14400	39	0x0027	0.0
19200	29	0x001D	0.0
28800	19	0x0013	0.0
38400	14	0x000E	0.0
57600	9	0x0009	0.0
76800	7	0x0007	6.7
115200	4	0x0004	0.0
230400	2	0x0002	20.0

Bit Rate	UBRR	UBRR (hex)	% of error
4.9152 Mhz
300	2047	0x07FF	0.0
600	1023	0x03FF	0.0
1200	511	0x01FF	0.0
2400	255	0x00FF	0.0
4800	127	0x007F	0.0
9600	63	0x003F	0.0
14400	42	0x002A	0.8
19200	31	0x001F	0.0
28800	20	0x0014	1.6
38400	15	0x000F	0.0
57600	10	0x000A	3.1
76800	7	0x0007	0.0
115200	4	0x0004	6.2
230400	2	0x0002	12.5

Bit Rate	UBRR	UBRR (hex)	% of error
5 Mhz
300	2082	0x0822	0.0
600	1041	0x0411	0.0
1200	520	0x0208	0.0
2400	259	0x0103	0.2
4800	129	0x0081	0.2
9600	64	0x0040	0.2
14400	42	0x002A	0.9
19200	32	0x0020	1.4
28800	21	0x0015	1.4
38400	15	0x000F	1.7
57600	10	0x000A	1.4
76800	7	0x0007	1.7
115200	4	0x0004	7.8
230400	2	0x0002	10.6

Bit Rate	UBRR	UBRR (hex)	% of error
5.0688 Mhz
300	2111	0x083F	0.0
600	1055	0x041F	0.0
1200	527	0x020F	0.0
2400	263	0x0107	0.0
4800	131	0x0083	0.0
9600	65	0x0041	0.0
14400	43	0x002B	0.0
19200	32	0x0020	0.0
28800	21	0x0015	0.0
38400	16	0x0010	3.0
57600	10	0x000A	0.0
76800	7	0x0007	3.0
115200	5	0x0005	9.1
230400	2	0x0002	9.1

Bit Rate	UBRR	UBRR (hex)	% of error
6.144 Mhz
300	2559	0x09FF	0.0
600	1279	0x04FF	0.0
1200	639	0x027F	0.0
2400	319	0x013F	0.0
4800	159	0x009F	0.0
9600	79	0x004F	0.0
14400	52	0x0034	0.6
19200	39	0x0027	0.0
28800	26	0x001A	1.2
38400	19	0x0013	0.0
57600	12	0x000C	2.5
76800	9	0x0009	0.0
115200	6	0x0006	5.0
230400	2	0x0002	10.0

Bit Rate	UBRR	UBRR (hex)	% of error
6.4 Mhz
300	2666	0x0A6A	0.0
600	1332	0x0534	0.0
1200	666	0x029A	0.0
2400	332	0x014C	0.1
4800	166	0x00A6	0.2
9600	82	0x0052	0.4
14400	55	0x0037	0.8
19200	41	0x0029	0.8
28800	27	0x001B	0.8
38400	20	0x0014	0.8
57600	13	0x000D	0.8
76800	9	0x0009	4.0
115200	6	0x0006	0.8
230400	2	0x0002	13.6

Bit Rate	UBRR	UBRR (hex)	% of error
7.3728 Mhz
300	3071	0x0BFF	0.0
600	1535	0x05FF	0.0
1200	767	0x02FF	0.0
2400	383	0x017F	0.0
4800	191	0x00BF	0.0
9600	95	0x005F	0.0
14400	63	0x003F	0.0
19200	47	0x002F	0.0
28800	31	0x001F	0.0
38400	23	0x0017	0.0
57600	15	0x000F	0.0
76800	11	0x000B	0.0
115200	7	0x0007	0.0
230400	3	0x0003	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
8 Mhz
300	3332	0x0D04	0.0
600	1666	0x0682	0.0
1200	832	0x0340	0.0
2400	416	0x01A0	0.1
4800	207	0x00CF	0.2
9600	103	0x0067	0.2
14400	68	0x0044	0.6
19200	51	0x0033	0.2
28800	34	0x0022	0.8
38400	25	0x0019	0.2
57600	16	0x0010	2.1
76800	12	0x000C	0.2
115200	8	0x0008	3.7
230400	3	0x0003	7.8

Bit Rate	UBRR	UBRR (hex)	% of error
9.216 Mhz
300	3839	0x0EFF	0.0
600	1919	0x077F	0.0
1200	959	0x03BF	0.0
2400	479	0x01DF	0.0
4800	239	0x00EF	0.0
9600	119	0x0077	0.0
14400	79	0x004F	0.0
19200	59	0x003B	0.0
28800	39	0x0027	0.0
38400	29	0x001D	0.0
57600	19	0x0013	0.0
76800	14	0x000E	0.0
115200	9	0x0009	0.0
230400	4	0x0004	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
10 Mhz
300	4166	0x1046	0.0
600	2082	0x0822	0.0
1200	1041	0x0411	0.0
2400	520	0x0208	0.0
4800	259	0x0103	0.2
9600	129	0x0081	0.2
14400	86	0x0056	0.2
19200	64	0x0040	0.2
28800	42	0x002A	0.9
38400	32	0x0020	1.4
57600	21	0x0015	1.4
76800	15	0x000F	1.7
115200	10	0x000A	1.4
230400	4	0x0004	7.8

Bit Rate	UBRR	UBRR (hex)	% of error
10.24 Mhz
300	4266	0x10AA	0.0
600	2132	0x0854	0.0
1200	1066	0x042A	0.0
2400	532	0x0214	0.1
4800	266	0x010A	0.1
9600	132	0x0084	0.2
14400	88	0x0058	0.1
19200	66	0x0042	0.5
28800	43	0x002B	1.0
38400	32	0x0020	1.0
57600	21	0x0015	1.0
76800	16	0x0010	2.0
115200	10	0x000A	1.0
230400	5	0x0005	8.0

Bit Rate	UBRR	UBRR (hex)	% of error
11.0592 Mhz
300	4607	0x11FF	0.0
600	2303	0x08FF	0.0
1200	1151	0x047F	0.0
2400	575	0x023F	0.0
4800	287	0x011F	0.0
9600	143	0x008F	0.0
14400	95	0x005F	0.0
19200	71	0x0047	0.0
28800	47	0x002F	0.0
38400	35	0x0023	0.0
57600	23	0x0017	0.0
76800	17	0x0011	0.0
115200	11	0x000B	0.0
230400	5	0x0005	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
12 Mhz
300	4999	0x1387	0.0
600	2499	0x09C3	0.0
1200	1249	0x04E1	0.0
2400	624	0x0270	0.0
4800	312	0x0138	0.2
9600	155	0x009B	0.2
14400	103	0x0067	0.2
19200	77	0x004D	0.2
28800	51	0x0033	0.2
38400	38	0x0026	0.2
57600	25	0x0019	0.2
76800	19	0x0013	2.4
115200	12	0x000C	0.2
230400	6	0x0006	7.5

Bit Rate	UBRR	UBRR (hex)	% of error
12.288 Mhz
300	5119	0x13FF	0.0
600	2559	0x09FF	0.0
1200	1279	0x04FF	0.0
2400	639	0x027F	0.0
4800	319	0x013F	0.0
9600	159	0x009F	0.0
14400	106	0x006A	0.3
19200	79	0x004F	0.0
28800	52	0x0034	0.6
38400	39	0x0027	0.0
57600	26	0x001A	1.2
76800	19	0x0013	0.0
115200	12	0x000C	2.5
230400	6	0x0006	5.0

Bit Rate	UBRR	UBRR (hex)	% of error
12.8 Mhz
300	5332	0x14D4	0.0
600	2666	0x0A6A	0.0
1200	1332	0x0534	0.0
2400	666	0x029A	0.0
4800	332	0x014C	0.1
9600	166	0x00A6	0.2
14400	110	0x006E	0.1
19200	82	0x0052	0.4
28800	55	0x0037	0.8
38400	41	0x0029	0.8
57600	27	0x001B	0.8
76800	20	0x0014	0.8
115200	13	0x000D	0.8
230400	6	0x0006	0.8

Bit Rate	UBRR	UBRR (hex)	% of error
14.318182 Mhz
300	5965	0x174D	0.0
600	2982	0x0BA6	0.0
1200	1490	0x05D2	0.0
2400	745	0x02E9	0.0
4800	372	0x0174	0.0
9600	185	0x00B9	0.2
14400	123	0x007B	0.2
19200	92	0x005C	0.2
28800	61	0x003D	0.2
38400	46	0x002E	0.8
57600	30	0x001E	0.2
76800	22	0x0016	1.3
115200	15	0x000F	3.0
230400	7	0x0007	3.0

Bit Rate	UBRR	UBRR (hex)	% of error
14.7456 Mhz
300	6143	0x17FF	0.0
600	3071	0x0BFF	0.0
1200	1535	0x05FF	0.0
2400	767	0x02FF	0.0
4800	383	0x017F	0.0
9600	191	0x00BF	0.0
14400	127	0x007F	0.0
19200	95	0x005F	0.0
28800	63	0x003F	0.0
38400	47	0x002F	0.0
57600	31	0x001F	0.0
76800	23	0x0017	0.0
115200	15	0x000F	0.0
230400	7	0x0007	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
16 Mhz
300	6666	0x1A0A	0.0
600	3332	0x0D04	0.0
1200	1666	0x0682	0.0
2400	832	0x0340	0.0
4800	416	0x01A0	0.1
9600	207	0x00CF	0.2
14400	138	0x008A	0.1
19200	103	0x0067	0.2
28800	68	0x0044	0.6
38400	51	0x0033	0.2
57600	34	0x0022	0.8
76800	25	0x0019	0.2
115200	16	0x0010	2.1
230400	8	0x0008	3.7

Bit Rate	UBRR	UBRR (hex)	% of error
16.8 Mhz
300	6999	0x1B57	0.0
600	3499	0x0DAB	0.0
1200	1749	0x06D5	0.0
2400	874	0x036A	0.0
4800	437	0x01B5	0.1
9600	218	0x00DA	0.1
14400	145	0x0091	0.1
19200	108	0x006C	0.3
28800	72	0x0048	0.1
38400	54	0x0036	0.6
57600	35	0x0023	1.3
76800	26	0x001A	1.3
115200	17	0x0011	1.3
230400	8	0x0008	1.3

Bit Rate	UBRR	UBRR (hex)	% of error
18.432 Mhz
300	7679	0x1DFF	0.0
600	3839	0x0EFF	0.0
1200	1919	0x077F	0.0
2400	959	0x03BF	0.0
4800	479	0x01DF	0.0
9600	239	0x00EF	0.0
14400	159	0x009F	0.0
19200	119	0x0077	0.0
28800	79	0x004F	0.0
38400	59	0x003B	0.0
57600	39	0x0027	0.0
76800	29	0x001D	0.0
115200	19	0x0013	0.0
230400	9	0x0009	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
20 Mhz
300	8332	0x208C	0.0
600	4166	0x1046	0.0
1200	2082	0x0822	0.0
2400	1041	0x0411	0.0
4800	520	0x0208	0.0
9600	259	0x0103	0.2
14400	173	0x00AD	0.2
19200	129	0x0081	0.2
28800	86	0x0056	0.2
38400	64	0x0040	0.2
57600	42	0x002A	0.9
76800	32	0x0020	1.4
115200	21	0x0015	1.4
230400	10	0x000A	1.4

Bit Rate	UBRR	UBRR (hex)	% of error
30 Mhz
300	12499	0x30D3	0.0
600	6249	0x1869	0.0
1200	3124	0x0C34	0.0
2400	1562	0x061A	0.0
4800	780	0x030C	0.0
9600	390	0x0186	0.1
14400	259	0x0103	0.2
19200	194	0x00C2	0.2
28800	129	0x0081	0.2
38400	97	0x0061	0.4
57600	64	0x0040	0.2
76800	48	0x0030	0.4
115200	32	0x0020	1.4
230400	15	0x000F	1.7

Bit Rate	UBRR	UBRR (hex)	% of error
32.768 Mhz
300	13652	0x3554	0.0
600	6826	0x1AAA	0.0
1200	3412	0x0D54	0.0
2400	1706	0x06AA	0.0
4800	852	0x0354	0.0
9600	426	0x01AA	0.1
14400	283	0x011B	0.2
19200	212	0x00D4	0.2
28800	141	0x008D	0.2
38400	106	0x006A	0.3
57600	70	0x0046	0.2
76800	52	0x0034	0.6
115200	35	0x0023	1.2
230400	17	0x0011	1.2

Bit Rate	UBRR	UBRR (hex)	% of error
40 Mhz
300	16666	0x411A	0.0
600	8332	0x208C	0.0
1200	4166	0x1046	0.0
2400	2082	0x0822	0.0
4800	1041	0x0411	0.0
9600	520	0x0208	0.0
14400	346	0x015A	0.1
19200	259	0x0103	0.2
28800	173	0x00AD	0.2
38400	129	0x0081	0.2
57600	86	0x0056	0.2
76800	64	0x0040	0.2
115200	42	0x002A	0.9
230400	21	0x0015	1.4

Legend:
UBRR out of range
UBRR and clock speed are a perfect match
UBRR and clock speed are less than 1% off
UBRR and clock speed are between 1% and 2% off
UBRR and clock speed are between 2% and 3% off
UBRR and clock speed are between 3% and 5% off
UBRR and clock speed is over 5% off

I call this a "baud rate calculator", however, "baud rate" is technically an incorrect term. It should be called a "bit rate calculator". Because people misuse the term "baud" so frequently, many do not know there is a difference between "bit rate" and "baud rate". I use the term "baud rate" on the title, knowing it is wrong, so people would be able to find this page, when searching the web, however, all other references are as "bit rate".

NOTE: This page was originally written when there was only one UBRR register, but newer AVR models have 2 UBRR registers, so some of the lower values that show out of range, are really in range. I will update this page some time in the future.

How to use this page:
Without entering anything, you can get a list of the UBRR settings for many popular clock speeds, and serial port bit rates. What makes this program special, is the fact that you can tell it what serial port bit rate you want, and it will tell you all the possible clock speeds that will generate your desired serial port bit rate. You can also give it a clock speed, and it will tell you all the possible serial port bit rates that can be producted with that clock speed. This is very handy when you are searching through your "junk pile", looking for the right crystal, or oscillator to generate a given serial port bit rate.
If you enter a serial port bit rate, not already listed, then the serial port bit rate will be listed as the last entry on each clock speed table. If you enter a clock speed that is not already listed, then a new clock speed table will be added to the end of the list.

If you would like to contact me about this program, if you have any questions or requests then stop by channel #avr on the FreeNode IRC network.

AVRBaudCalc is ©2005-2013 by WormFood

Bit Rate		Show table of all possible clock speeds, for a given bit rate
Clock Freq, in Mhz		Show table of all possible bit rates, for a given clock speed
		show additional double speed mode information
		show additional synchronous mode information