WormFood's AVR Baud Rate Calculator

Bit Rate	UBRR	UBRR (hex)	% of error
32.768 Khz
300	6	0x0006	2.5
600	2	0x0002	12.1
1200	1	0x0001	17.2
2400	0	0x0000	17.2
4800	0	0x0000	134.4
9600	0	0x0000	368.8
14400	0	0x0000	603.1
19200	0	0x0000	837.5
28800	0	0x0000	1306.2
38400	0	0x0000	1775.0
57600	0	0x0000	2712.5
76800	0	0x0000	3650.0
115200	0	0x0000	5525.0
230400	0	0x0000	11150.0

Bit Rate	UBRR	UBRR (hex)	% of error
1.8432 Mhz
300	383	0x017F	0.0
600	191	0x00BF	0.0
1200	95	0x005F	0.0
2400	47	0x002F	0.0
4800	23	0x0017	0.0
9600	11	0x000B	0.0
14400	7	0x0007	0.0
19200	5	0x0005	0.0
28800	3	0x0003	0.0
38400	2	0x0002	0.0
57600	1	0x0001	0.0
76800	1	0x0001	33.3
115200	0	0x0000	0.0
230400	0	0x0000	100.0

Bit Rate	UBRR	UBRR (hex)	% of error
2.4576 Mhz
300	511	0x01FF	0.0
600	255	0x00FF	0.0
1200	127	0x007F	0.0
2400	63	0x003F	0.0
4800	31	0x001F	0.0
9600	15	0x000F	0.0
14400	10	0x000A	3.1
19200	7	0x0007	0.0
28800	4	0x0004	6.2
38400	3	0x0003	0.0
57600	2	0x0002	12.5
76800	1	0x0001	0.0
115200	0	0x0000	25.0
230400	0	0x0000	50.0

Bit Rate	UBRR	UBRR (hex)	% of error
3.072 Mhz
300	639	0x027F	0.0
600	319	0x013F	0.0
1200	159	0x009F	0.0
2400	79	0x004F	0.0
4800	39	0x0027	0.0
9600	19	0x0013	0.0
14400	12	0x000C	2.5
19200	9	0x0009	0.0
28800	6	0x0006	5.0
38400	4	0x0004	0.0
57600	2	0x0002	10.0
76800	2	0x0002	20.0
115200	1	0x0001	20.0
230400	0	0x0000	20.0

Bit Rate	UBRR	UBRR (hex)	% of error
3.2768 Mhz
300	682	0x02AA	0.0
600	340	0x0154	0.1
1200	170	0x00AA	0.2
2400	84	0x0054	0.4
4800	42	0x002A	0.8
9600	20	0x0014	1.6
14400	13	0x000D	1.6
19200	10	0x000A	3.1
28800	6	0x0006	1.6
38400	4	0x0004	6.2
57600	3	0x0003	12.5
76800	2	0x0002	12.5
115200	1	0x0001	12.5
230400	0	0x0000	12.5

Bit Rate	UBRR	UBRR (hex)	% of error
3.579545 Mhz
300	745	0x02E9	0.0
600	372	0x0174	0.0
1200	185	0x00B9	0.2
2400	92	0x005C	0.2
4800	46	0x002E	0.8
9600	22	0x0016	1.3
14400	15	0x000F	3.0
19200	11	0x000B	3.0
28800	7	0x0007	3.0
38400	5	0x0005	3.0
57600	3	0x0003	3.0
76800	2	0x0002	3.0
115200	1	0x0001	3.0
230400	0	0x0000	3.0

Bit Rate	UBRR	UBRR (hex)	% of error
3.6864 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
3.93216 Mhz
300	818	0x0332	0.0
600	409	0x0199	0.1
1200	204	0x00CC	0.1
2400	101	0x0065	0.4
4800	50	0x0032	0.4
9600	25	0x0019	1.6
14400	16	0x0010	0.4
19200	12	0x000C	1.6
28800	8	0x0008	5.5
38400	5	0x0005	6.2
57600	3	0x0003	6.2
76800	2	0x0002	6.2
115200	1	0x0001	6.2
230400	0	0x0000	6.2

Bit Rate	UBRR	UBRR (hex)	% of error
4 Mhz
300	832	0x0340	0.0
600	416	0x01A0	0.1
1200	207	0x00CF	0.2
2400	103	0x0067	0.2
4800	51	0x0033	0.2
9600	25	0x0019	0.2
14400	16	0x0010	2.1
19200	12	0x000C	0.2
28800	8	0x0008	3.7
38400	6	0x0006	7.5
57600	3	0x0003	7.8
76800	2	0x0002	7.8
115200	1	0x0001	7.8
230400	0	0x0000	7.8

Bit Rate	UBRR	UBRR (hex)	% of error
4.194304 Mhz
300	873	0x0369	0.0
600	436	0x01B4	0.0
1200	217	0x00D9	0.2
2400	108	0x006C	0.2
4800	54	0x0036	0.7
9600	26	0x001A	1.1
14400	17	0x0011	1.1
19200	13	0x000D	2.5
28800	8	0x0008	1.1
38400	6	0x0006	2.5
57600	4	0x0004	9.9
76800	2	0x0002	12.1
115200	1	0x0001	12.1
230400	0	0x0000	12.1

Bit Rate	UBRR	UBRR (hex)	% of error
4.433619 Mhz
300	923	0x039B	0.0
600	461	0x01CD	0.0
1200	230	0x00E6	0.0
2400	114	0x0072	0.4
4800	57	0x0039	0.5
9600	28	0x001C	0.5
14400	18	0x0012	1.3
19200	13	0x000D	3.0
28800	9	0x0009	3.9
38400	6	0x0006	3.0
57600	4	0x0004	3.9
76800	3	0x0003	10.9
115200	1	0x0001	16.9
230400	0	0x0000	16.9

Bit Rate	UBRR	UBRR (hex)	% of error
4.608 Mhz
300	959	0x03BF	0.0
600	479	0x01DF	0.0
1200	239	0x00EF	0.0
2400	119	0x0077	0.0
4800	59	0x003B	0.0
9600	29	0x001D	0.0
14400	19	0x0013	0.0
19200	14	0x000E	0.0
28800	9	0x0009	0.0
38400	7	0x0007	6.7
57600	4	0x0004	0.0
76800	3	0x0003	6.7
115200	2	0x0002	20.0
230400	0	0x0000	20.0

Bit Rate	UBRR	UBRR (hex)	% of error
4.9152 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
5 Mhz
300	1041	0x0411	0.0
600	520	0x0208	0.0
1200	259	0x0103	0.2
2400	129	0x0081	0.2
4800	64	0x0040	0.2
9600	32	0x0020	1.4
14400	21	0x0015	1.4
19200	15	0x000F	1.7
28800	10	0x000A	1.4
38400	7	0x0007	1.7
57600	4	0x0004	7.8
76800	3	0x0003	1.7
115200	2	0x0002	10.6
230400	0	0x0000	26.3

Bit Rate	UBRR	UBRR (hex)	% of error
5.0688 Mhz
300	1055	0x041F	0.0
600	527	0x020F	0.0
1200	263	0x0107	0.0
2400	131	0x0083	0.0
4800	65	0x0041	0.0
9600	32	0x0020	0.0
14400	21	0x0015	0.0
19200	16	0x0010	3.0
28800	10	0x000A	0.0
38400	7	0x0007	3.0
57600	5	0x0005	9.1
76800	3	0x0003	3.0
115200	2	0x0002	9.1
230400	0	0x0000	27.3

Bit Rate	UBRR	UBRR (hex)	% of error
6.144 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
6.4 Mhz
300	1332	0x0534	0.0
600	666	0x029A	0.0
1200	332	0x014C	0.1
2400	166	0x00A6	0.2
4800	82	0x0052	0.4
9600	41	0x0029	0.8
14400	27	0x001B	0.8
19200	20	0x0014	0.8
28800	13	0x000D	0.8
38400	9	0x0009	4.0
57600	6	0x0006	0.8
76800	4	0x0004	4.0
115200	2	0x0002	13.6
230400	1	0x0001	15.2

Bit Rate	UBRR	UBRR (hex)	% of error
7.3728 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
8 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
9.216 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
10 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
10.24 Mhz
300	2132	0x0854	0.0
600	1066	0x042A	0.0
1200	532	0x0214	0.1
2400	266	0x010A	0.1
4800	132	0x0084	0.2
9600	66	0x0042	0.5
14400	43	0x002B	1.0
19200	32	0x0020	1.0
28800	21	0x0015	1.0
38400	16	0x0010	2.0
57600	10	0x000A	1.0
76800	7	0x0007	4.0
115200	5	0x0005	8.0
230400	2	0x0002	8.0

Bit Rate	UBRR	UBRR (hex)	% of error
11.0592 Mhz
300	2303	0x08FF	0.0
600	1151	0x047F	0.0
1200	575	0x023F	0.0
2400	287	0x011F	0.0
4800	143	0x008F	0.0
9600	71	0x0047	0.0
14400	47	0x002F	0.0
19200	35	0x0023	0.0
28800	23	0x0017	0.0
38400	17	0x0011	0.0
57600	11	0x000B	0.0
76800	8	0x0008	0.0
115200	5	0x0005	0.0
230400	2	0x0002	0.0

Bit Rate	UBRR	UBRR (hex)	% of error
12 Mhz
300	2499	0x09C3	0.0
600	1249	0x04E1	0.0
1200	624	0x0270	0.0
2400	312	0x0138	0.2
4800	155	0x009B	0.2
9600	77	0x004D	0.2
14400	51	0x0033	0.2
19200	38	0x0026	0.2
28800	25	0x0019	0.2
38400	19	0x0013	2.4
57600	12	0x000C	0.2
76800	9	0x0009	2.4
115200	6	0x0006	7.5
230400	2	0x0002	7.8

Bit Rate	UBRR	UBRR (hex)	% of error
12.288 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
12.8 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
14.318182 Mhz
300	2982	0x0BA6	0.0
600	1490	0x05D2	0.0
1200	745	0x02E9	0.0
2400	372	0x0174	0.0
4800	185	0x00B9	0.2
9600	92	0x005C	0.2
14400	61	0x003D	0.2
19200	46	0x002E	0.8
28800	30	0x001E	0.2
38400	22	0x0016	1.3
57600	15	0x000F	3.0
76800	11	0x000B	3.0
115200	7	0x0007	3.0
230400	3	0x0003	3.0

Bit Rate	UBRR	UBRR (hex)	% of error
14.7456 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
16 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
16.8 Mhz
300	3499	0x0DAB	0.0
600	1749	0x06D5	0.0
1200	874	0x036A	0.0
2400	437	0x01B5	0.1
4800	218	0x00DA	0.1
9600	108	0x006C	0.3
14400	72	0x0048	0.1
19200	54	0x0036	0.6
28800	35	0x0023	1.3
38400	26	0x001A	1.3
57600	17	0x0011	1.3
76800	13	0x000D	2.4
115200	8	0x0008	1.3
230400	4	0x0004	9.7

Bit Rate	UBRR	UBRR (hex)	% of error
18.432 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
20 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
30 Mhz
300	6249	0x1869	0.0
600	3124	0x0C34	0.0
1200	1562	0x061A	0.0
2400	780	0x030C	0.0
4800	390	0x0186	0.1
9600	194	0x00C2	0.2
14400	129	0x0081	0.2
19200	97	0x0061	0.4
28800	64	0x0040	0.2
38400	48	0x0030	0.4
57600	32	0x0020	1.4
76800	23	0x0017	1.7
115200	15	0x000F	1.7
230400	7	0x0007	1.7

Bit Rate	UBRR	UBRR (hex)	% of error
32.768 Mhz
300	6826	0x1AAA	0.0
600	3412	0x0D54	0.0
1200	1706	0x06AA	0.0
2400	852	0x0354	0.0
4800	426	0x01AA	0.1
9600	212	0x00D4	0.2
14400	141	0x008D	0.2
19200	106	0x006A	0.3
28800	70	0x0046	0.2
38400	52	0x0034	0.6
57600	35	0x0023	1.2
76800	26	0x001A	1.2
115200	17	0x0011	1.2
230400	8	0x0008	1.2

Bit Rate	UBRR	UBRR (hex)	% of error
40 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

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