What is Impact Factor

Impact factor is a measure of the frequency with which the "average article" published in a given scholarly journal has been cited in a particular year or period and is often used to measure or describe the importance of a particular journal to its field. The Thomson-Reuters (formerly Institute for Scientific Information (ISI)) ranks, evaluates, and compares journals within subject categories and publishes the results in Journal Citation Reports.  The new rankings come out in the Spring, for the previous year's journals.  Three years worth of data are required to calculate a Journal Impact Factor.

The formula to determine the 2007 impact factor for a journal would be calculated as follows:

A = the number of times articles published in the journal during 2006-7 were cited by other journals during 2008
B = the number of articles or reviews that were published in the journal during 2006-7

2007 Impact factor for a journal = A/B

  

list of impact factor journals

eg for 2013 Indo American Journal of Pharmaceutical Research 0.85 www.iajpr.com (Pharma)

Journal Names	2006  cited	Impact Factor	Immed. Index	Articles	Half-life
CELL ONCOL	2391	3.089	0.5	62	8.2
CELL PHYSIOL BIOCHEM	148	2.979	0.357	14	2.1
CELL PROLIFERAT	1115	3.558	0.206	63	3.8
CELL RES	912	4.492	0.356	45	3.9
CELL SIGNAL	1157	3.426	0.545	101	2.4
CELL STRESS CHAPERON	4590	4.887	1.213	225	4.1
CELL STRUCT FUNCT	1195	3.097	0.25	40	5.1
CELL TISSUE RES	1120	2.143	1.5	4	6.8
EXP HEAT TRANSFER	2441	1.112	0.235	153	6.8
EXP MOL MED	157	0.361	0.1	20	8.5
EXP NEUROL	965	2.296	0.265	83	3.6
EXP TECHNIQUES	13008	4.156	0.889	316	6.9
EXP THERM FLUID SCI	162	0.274	0.133	45	5.4
EXP THERM FLUID SCI	1178	0.894	0.075	80	6.9
EXPERT OPIN BIOL TH	1178	0.894	0.075	80	6.9
EXPERT REV MED DEVIC	1405	2.705	0.385	104	2.8
EXPERT REV PROTEOMIC	81	0.791	0.141	64
EXPERT SYST APPL	350	2.991	0.581	31	1.8
EXTREMOPHILES	884	0.957	0.123	162	4.4
FARADAY DISCUSS	999	1.921	0.164	67	5.1
FASEB J	4045	4.731	2.766	47	99.9
FATIGUE FRACT ENG M	30621	6.721	1.241	449	5.8
FEBS J	1387	0.756	0.097	93	7.7
FEBS LETT	1879	3.033	0.463	467	1.4
FEMS IMMUNOL MED MIC	53127	3.372	0.589	1068	7.7
FEMS MICROBIOL ECOL	2626	2.281	0.34	156	5.2
FEMS MICROBIOL LETT	4812	3.157	0.489	186	5.3
FEMS MICROBIOL REV	13243	2.068	0.344	485	6.7
IEE P-ELECT POW APPL	1127	0.927	0.047	85	7.2
IEE P-GENER TRANSM D	609	0.29	0.036	110	8.3
IEE P-MICROW ANTEN P	819	0.293	0.011	91	8.3
IEE P-OPTOELECTRON	686	0.572	0.033	91	9
IEE P-SCI MEAS TECH	544	0.632	0.035	57	8
IEE P-VIS IMAGE SIGN	476	0.461	0.081	37	99.9
IEE REV	382	0.461	0.04	101	6.2
IEEE ACM T COMPUT BI	57	0.126	0	17
IEEE ACM T NETWORK	121	2.283	0.389	36	2.2
IEEE AERO EL SYS MAG	3614	1.789	0.131	107	7.4
IEEE ANTENN PROPAG M	172	0.423	0	78	4.4
IEEE CIRCUITS DEVICE	847	0.873	0.169	59	6.2
IEEE COMMUN MAG	241	1.22	0.067	15	5.7
IEEE ELECTR DEVICE L	3691	1.678	0.224	165	5.2
IEEE ELECTR INSUL M	5233	2.716	0.5	278	4.9
IEEE ENG MED BIOL	199	0.612	0	22	6.4
IEEE IND APPL MAG	1095	0.94	0.067	60	6.8
IEEE INSTRU MEAS MAG	181	0.238	0.023	43	5.5
IEEE INTELL SYST	127	0.327	0.051	39	4.9
IEEE J OCEANIC ENG	1120	2.413	0.176	68	5.1
IEEE J QUANTUM ELECT	1106	1.259	0.391	46	6.7
IEEE J QUANTUM ELECT	10005	2.262	0.48	150	99.9
IEEE J SEL AREA COMM	10005	2.262	0.48	150	99.9
IEEE J SEL TOP QUANT	6813	1.816	0.209	235	6.9
IEEE J SOLID-ST CIRC	4712	2.842	0.191	188	5.3
IEEE MICROW MAG	7148	2.002	0.234	290	6.8
IEEE MICROW WIREL CO	210	1.357	0.167	30	4
IEEE NETWORK	1428	1.424	0.159	226	3
IEEE PERVAS COMPUT	1135	2.211	0.057	35	6.2
IEEE PHOTONIC TECH L	447	2.062	0.093	43	3.5
IEEE PHOTONIC TECH L	13528	2.353	0.461	868	4.5
IEEE SENS J	13528	2.353	0.461	868	4.5
IEEE SENS J	834	1.117	0.135	223	3.3
IEEE SIGNAL PROC LET	834	1.117	0.135	223	3.3
IEEE SIGNAL PROC MAG	1367	0.722	0.039	181	5.1
IEEE SPECTRUM	1466	2.655	1.212	52	5.4
IEEE T ADV PACKAGING	728	0.84	0.279	61	6.5
IEEE T AERO ELEC SYS	763	1.443	0.106	94	4.8
IEEE T ANTENN PROPAG	2316	0.836	0.233	86	99.9
IEEE T APPL SUPERCON	9487	1.48	0.245	477	9.9
IEEE T APPL SUPERCON	3096	0.717	1.654	26	4
IEEE T AUDIO SPEECH	3096	0.717	1.654	26	4
IEEE T AUTOMAT CONTR	29		0.136	198
IEEE T BIO-MED ENG	15573	2.772	0.156	256	99.9
IEEE T BROADCAST	7328	2.302	0.233	309	8.6
IEEE T CIRC SYST VID	514	1.235	0.304	69	4.1
IEEE T CIRCUITS-I	3406	1.743	0.146	144	5.7
IEEE T CIRCUITS-II	3751	1.139	0.103	263	6.1
IEEE T COMMUN	1773	0.922	0.059	287	7.1
IEEE T COMPON PACK T	8270	1.208	0.147	258	9.2
IEEE T COMPUT	1070	0.816	0.055	109	5.9
IEEE T COMPUT AID D	5518	1.426	0.243	140	99.9
IEEE T CONSUM ELECTR	2357	0.838	0.077	234	8
IEEE T CONTR SYST T	1184	0.727	0.081	211	5.2
IEEE T DEVICE MAT RE	1580	1.211	0.148	115	6
IEEE T DEVICE MAT RE	309	1.373	0.068	73	2.4
IEEE T DIELECT EL IN	309	1.373	0.068	73	2.4
IEEE T DIELECT EL IN	1228	0.771	0.087	160	6.3
IEEE T EDUC	1228	0.771	0.087	160	6.3
IEEE T ELECTROMAGN C	393	0.362	0.019	54	6.8
IEEE T ELECTRON DEV	968	0.77	0.173	98	8.5
IEEE T ELECTRON DEV	10251	2.052	0.34	423	7.7
IEEE T ELECTRON PACK	10251	2.052	0.34	423	7.7
IEEE T ENERGY CONVER	311	1	0.111	36	4.7
IEEE T ENG MANAGE	1246	0.716	0.066	106	7.6
IEEE T FUZZY SYST	800	0.825	0.22	41	9.2
IEEE T GEOSCI REMOTE	2579	1.803	0.085	71	6.9
IEEE T IMAGE PROCESS	7698	1.752	1.055	343	6.7
IEEE T IND APPL	7045	2.715	0.307	322	6.7
IEEE T IND ELECTRON	3663	0.611	0.068	161	9.5
IEEE T IND INFORM	2175	0.59	0.05	200	6.9
IEEE T INFORM THEORY	36	0.923	0.4	30
IEEE T INSTRUM MEAS	14149	1.938	0.398	452	8.8
IEEE T INTELL TRANSP	2461	0.572	0.074	299	7.6
IEEE T KNOWL DATA EN	327	1.434	0.163	49	4
IEEE T MAGN	2125	2.063	0.159	126	5.5
IEEE T MAGN	10422	0.938	0.151	910	7.3
IEEE T MED IMAGING	10422	0.938	0.151	910	7.3
IEEE T MICROW THEORY	7766	3.757	0.532	141	6.7
IEEE T NANOBIOSCI	10815	2.027	0.265	529	7.8
IEEE T NANOTECHNOL	316	2.592	0.162	37	2.7
IEEE T NANOTECHNOL	713	1.909	0.207	111	3
IEEE T NEUR SYS REH	713	1.909	0.207	111	3
IEEE T NEURAL NETWOR	627	1.842	0.221	68	3.4
IEEE T NUCL SCI	6167	2.62	0.28	150	7.5
IEEE T PARALL DISTR	8582	1.497	0.2	606	6.8
IEEE T PATTERN ANAL	1669	1.246	0.112	116	6.9
IEEE T PLASMA SCI	14708	4.306	0.489	182	9.2
IEEE T POWER DELIVER	3821	1.144	0.179	329	6.5
IEEE T POWER ELECTR	2692	0.496	0.066	274	9
IEEE T POWER SYST	2169	1.029	0.049	204	7
IEEE T RELIAB	4094	0.922	0.066	228	8.2
IEEE T SEMICONDUCT M	1297	0.8	0.033	61	99.9
IEEE T SEMICONDUCT M	852	0.785	0.115	52	7.2
IEEE T SIGNAL PROCES	852	0.785	0.115	52	7.2
IEEE T SOFTWARE ENG	8390	1.57	0.203	434	7.5
IEEE T SPEECH AUDI P	3203	2.132	0.158	57	99.9
IEEE T ULTRASON FERR	1687	1.006		0	6.6
IEEE T VEH TECHNOL	4384	1.729	0.245	261	6.9
IEEE T VLSI SYST	2783	1.071	0.103	174	7.7
IEEE T WIREL COMMUN	1027	0.771	0.052	134	5.6
IEEE TECHNOL SOC MAG	1383	1.184	0.077	427	2.9
IEEE WIREL COMMUN	53	0.512	0.05	20
IEEE-ASME T MECH	574	2.577	0.05	60	3.1
IEICE T COMMUN	798	0.979	0.074	81	5.3
IEICE T ELECTRON	1046	0.29	0.041	489	4.3
IEICE T FUND ELECTR	1102	0.508	0.05	298	4.6
IETE J RES	1132	0.312	0.049	508	4.8
IETE TECH REV	19	0.05	0	25
IIE TRANS	26	0.023	0	12
IMAGE VISION COMPUT	1839	0.637	0.058	86	99.9
IMMUNITY	1770	1.171	0.093	118	6.4
IMMUNOBIOLOGY	22744	18.306	3.556	133	5.8
IMMUNOGENETICS	1401	1.867	0.24	75	7.1
IMMUNOL ALLERGY CLIN	3896	2.852	0.491	106	6.7
IMMUNOL CELL BIOL	487	3.178	0.163	43	3.1
IMMUNOL INVEST	1827	2.482	0.567	67	5.5
IMMUNOL LETT	490	1.276	0	26	8.9
IMMUNOL RES	3336	2.352	0.529	157	4.7
IMMUNOL REV	1115	2.342	0.035	57	5.3
IMMUNOLOGY	8489	10.758	1.508	118	5
IMMUNOPHARM IMMUNOT	7992	3.674	0.52	175	8
IN VITRO CELL DEV-AN	461	0.654	0.107	56	7
IN VITRO CELL DEV-PL	1102	0.735	0.04	50	7.5
IND ENG CHEM RES	734	0.607	0	80	5.5
IND LUBR TRIBOL	16523	1.518	0.258	1067	6.4
IND ROBOT	74	0.444	0.25	32
INDIAN J BIOCHEM BIO	111	0.278	0.045	44	4.7
INDIAN J CHEM A	486	0.277	0.055	55	99.9
INDIAN J CHEM B	2092	0.631	0.168	167	9.8
INDIAN J CHEM TECHN	2660	0.491	0.049	283	99.9
INDIAN J CHEM TECHN	313	0.301	0.021	95	6.3
INDIAN J ENG MATER S	313	0.301	0.021	95	6.3
INDIAN J HETEROCY CH	123	0.277	0.028	72	4
INDIAN J MED RES	385	0.254	0.046	130	5.8
INDIAN J PHYS	1621	1.224	0.342	117	99.9
INDIAN J PURE AP PHY	425	0.195	0.024	124	9.4
INDOOR AIR	809	0.38	0.045	154	99.9
INDO AMERICAN JOURNAL OF PHARMACEUTICAL RESEARCH	1100	0.85	0.5	102	5.1
INFECT DIS CLIN N AM	198	0.535	0.2	65	3.6
INFECT IMMUN	1453	1.642	0.091	44	7
INFIN DIMENS ANAL QU	47906	4.004	0.645	819	7
INFLAMM RES	520	0.634	0.079	38	9.7
INFLAMMATION	2032	1.485	0.109	119	5.9
INFORM MIDEM	844	0.761		0	9.6
INFRARED PHYS TECHN	23	0.066	0	22
ING HIDRAUL MEX	793	0.97	0.186	70	8.2
ING QUIM	58	0.225	0.049	41
INORG CHEM	39	0.125	0.053	19
INORG CHEM COMMUN	58002	3.911	0.699	1443	8.4
INORG CHIM ACTA	3248	1.787	0.29	335	3.5
INORG REACT MECH	12777	1.674	0.433	631	7.9
INSECT BIOCHEM MOLEC	130	0.8	0.125	16	6.2
INSECT MOL BIOL	3746	2.711	0.464	97	6.3
INSTRUM EXP TECH+	1850	2.639	0.463	82	5.4
INSTRUM SCI TECHNOL	621	0.329	0.086	140	8
INT ARCH ALLERGY IMM	202	0.518	0.037	54	4.6
INT BIODETER BIODEGR	4497	2.524	0.269	145	7.2
INT GAS ENG MANAGE	1217	1.619	0.092	76	6.5
INT IMMUNOL	7	0.029	0	46
ISA T	8	0.064	0	44
ISOKINET EXERC SCI	217	0.3	0.062	48	6.5
ISOT ENVIRON HEALT S	132	0.222	0	30	6.9
ISR J CHEM	240	0.952	0.226	31	4.4
ISR J ZOOL	1093	1.174	0.125	24	99.9
ISSUES SCI TECHNOL	318	0.4			99.9
ITAL J ZOOL	167	0.43	0.179	28	5.6
ITE J	353	0.857	0.068	44	6.2
IUBMB LIFE	129	0.132	0.021	47	8.6
J ADHES SCI TECHNOL	1460	2.316	0.253	83	4.6
J ADHESION	1343	0.868	0.068	117	7.5
J ADV OXID TECHNOL	935	1.046	0.113	53	99.9
J ADV TRANSPORT	185	0.85	0.054	37	7.4
J AEROSOL SCI	102	0.731	0	16	7.8
J AEROSPACE ENG	4040	2.952	0.272	125	8.4
J AGR BIOL ENVIR ST	151	0.478	0.037	27	6.9
J AGR FOOD CHEM	328	0.85	0	18	6.4
J AIR WASTE MANAGE	37636	2.322	0.341	1459	6
J AIRCRAFT	3106	1.441	0.286	161	6.9
J ALLERGY CLIN IMMUN	1658	0.456	0.066	243	9.5
J ALLOY COMPD	26391	8.829	1.79	338	5.4
J ALZHEIMERS DIS	13994	1.25	0.204	1217	5.3
J AM ASSOC LAB ANIM	974	3.058	0.532	62	3.2
J AM CHEM SOC	8		0.093	75
J VAC SCI TECHNOL B	7388	1.394	0.199	366	8.6
J VAC SCI TECHNOL B	10633	1.597	0.268	589	6.7
J VESTIBUL RES-EQUIL	10633	1.597	0.268	589	6.7
J VIB ACOUST	604	1.057	0	7	8.8