Clayton Kershaw has the lowest career ERA by an active pitcher, with an ERA of 2.50.

Interpreted as:

best career era with a minimum of 750 IP current players

	NAME	ERA	IP	G	W	L	W%	GS	SO	CG	SHO	SV	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	Clayton Kershaw C. Kershaw	2.50	2742.2	432	212	94	.693	429	2,968	25	15	0	2,091	762	835	227	678	44	1	28	10,816	103	9.74	2.22	4.38	0.74	27.4	6.3	1.01	.270	2.74	64	2.82	70	6.86	366.8
2	Jacob deGrom J. deGrom	2.54	1394.0	223	84	58	.592	223	1,692	4	2	0	1,073	393	430	125	315	23	0	13	5,485	28	10.92	2.03	5.37	0.81	30.8	5.7	1.00	.285	2.78	65	2.62	65	6.93	226.8
3	Kenley Jansen K. Jansen	2.55	876.1	880	49	36	.576	0	1,229	0	0	452	578	248	266	80	265	31	660	18	3,476	21	12.62	2.72	4.64	0.82	35.4	7.6	0.96	.266	2.73	64	2.52	62	5.94	147.2
4	Aroldis Chapman A. Chapman	2.62	769.1	807	57	45	.559	0	1,260	0	0	339	454	224	248	52	397	33	526	7	3,152	82	14.74	4.64	3.17	0.61	40.0	12.6	1.11	.285	2.90	64	2.41	58	5.31	146.4
5	Max Fried M. Fried	3.02	916.0	173	77	36	.681	156	893	6	4	0	808	307	341	78	253	38	10	6	3,746	39	8.77	2.49	3.53	0.77	23.8	6.8	1.16	.294	3.35	71	3.27	79	7.94	90
6	Chris Sale C. Sale	3.07	1981.2	377	138	85	.619	297	2,446	16	3	12	1,621	677	729	206	462	122	25	15	7,989	46	11.11	2.10	5.29	0.94	30.6	5.8	1.05	.298	3.31	72	2.90	69	7.36	283.8
7	Max Scherzer M. Scherzer	3.16	2881.0	467	215	112	.657	458	3,408	12	5	0	2,349	1,012	1,085	337	756	112	2	20	11,640	78	10.65	2.36	4.51	1.05	29.3	6.5	1.08	.286	3.39	76	3.18	77	7.34	307.8
8	Gerrit Cole G. Cole	3.18	1954.0	317	153	80	.657	317	2,251	8	5	0	1,627	690	740	217	500	61	0	8	7,861	58	10.37	2.30	4.50	1.00	28.6	6.4	1.09	.292	3.41	79	3.16	77	7.49	213.5
9	Blake Snell B. Snell	3.18	1105.2	213	77	58	.570	213	1,372	1	1	0	850	391	426	108	503	11	0	5	4,583	81	11.17	4.09	2.73	0.88	29.9	11.0	1.22	.287	3.47	78	3.35	80	6.92	100.7
10	Corbin Burnes C. Burnes	3.21	930.1	204	60	37	.619	143	1,076	0	0	2	731	332	367	101	266	37	16	2	3,763	42	10.41	2.57	4.05	0.98	28.6	7.1	1.07	.276	3.55	77	3.24	78	7.07	97.5
11	Shane Bieber S. Bieber	3.22	843.0	136	62	32	.660	134	958	5	2	0	752	302	323	94	188	18	1	1	3,415	34	10.23	2.01	5.10	1.00	28.1	5.5	1.12	.305	3.45	76	3.08	73	8.03	108
12	Justin Verlander J. Verlander	3.31	3440.1	531	262	148	.639	531	3,439	26	9	0	2,917	1,267	1,370	359	963	115	0	27	14,055	97	9.00	2.52	3.57	0.94	24.5	6.9	1.13	.279	3.58	78	3.42	81	7.63	306.4
13	Framber Valdez F. Valdez	3.34	916.2	162	69	43	.616	140	892	7	3	0	768	340	376	74	332	53	7	1	3,800	50	8.76	3.26	2.69	0.73	23.5	8.7	1.20	.283	3.69	81	3.53	85	7.54	62.9
14	Zack Wheeler Z. Wheeler	3.34	1616.0	265	105	71	.597	265	1,675	4	3	0	1,398	600	650	153	465	69	0	14	6,648	39	9.33	2.59	3.60	0.85	25.2	7.0	1.15	.290	3.62	84	3.31	80	7.79	148
15	Logan Webb L. Webb	3.36	891.2	152	57	41	.582	149	814	3	2	0	840	333	367	61	214	30	0	4	3,637	21	8.22	2.16	3.80	0.62	22.4	5.9	1.18	.309	3.70	82	3.05	76	8.48	97.6
16	Seth Lugo S. Lugo	3.36	885.2	340	58	43	.574	103	858	1	0	16	785	331	357	101	233	32	66	18	3,635	18	8.72	2.37	3.68	1.03	23.6	6.4	1.15	.284	3.63	83	3.61	87	7.98	53.3
17	Zac Gallen Z. Gallen	3.36	842.2	148	54	38	.587	148	914	2	2	0	693	315	333	91	271	33	0	2	3,451	32	9.76	2.89	3.37	0.97	26.5	7.9	1.14	.281	3.56	79	3.49	85	7.40	56.8
18	Sandy Alcantara S. Alcantara	3.40	924.0	151	43	57	.430	143	806	12	4	0	788	349	395	94	285	35	3	8	3,780	20	7.85	2.78	2.83	0.92	21.3	7.5	1.16	.271	3.85	81	3.79	91	7.68	38.2
19	Sonny Gray S. Gray	3.51	1766.1	312	113	94	.546	303	1,753	6	4	0	1,511	688	754	172	587	56	2	5	7,310	105	8.93	2.99	2.99	0.88	24.0	8.0	1.19	.282	3.84	85	3.53	85	7.70	122.5
20	Chris Bassitt C. Bassitt	3.55	1137.0	205	74	57	.565	192	1,059	2	2	0	1,037	448	485	121	363	85	6	6	4,793	32	8.38	2.87	2.92	0.96	22.1	7.6	1.23	.289	3.84	87	3.87	93	8.21	35.9
21	Luis Castillo L. Castillo	3.57	1256.1	216	74	78	.487	216	1,354	1	0	0	1,070	499	545	154	419	42	0	8	5,200	16	9.70	3.00	3.23	1.10	26.0	8.1	1.19	.284	3.90	86	3.71	88	7.67	74.4
22	Yu Darvish Y. Darvish	3.58	1706.0	282	110	88	.556	282	2,007	2	1	0	1,394	678	712	217	544	77	0	8	7,009	79	10.59	2.87	3.69	1.14	28.6	7.8	1.14	.283	3.76	85	3.53	84	7.35	125.8
23	Jack Flaherty J. Flaherty	3.60	857.0	164	56	43	.566	158	976	0	0	0	708	343	363	115	301	50	0	9	3,550	31	10.25	3.16	3.24	1.21	27.5	8.5	1.18	.281	3.81	88	3.87	93	7.44	26.4
24	Kyle Hendricks K. Hendricks	3.69	1600.1	280	97	83	.539	274	1,269	6	4	0	1,518	657	706	187	371	64	4	16	6,597	12	7.14	2.09	3.42	1.05	19.2	5.6	1.18	.283	3.97	90	3.91	95	8.54	38.1
25	Jose Quintana J. Quintana	3.72	1988.1	362	105	103	.505	336	1,736	2	2	0	1,937	821	886	202	596	53	7	23	8,326	74	7.86	2.70	2.91	0.91	20.9	7.2	1.27	.302	4.01	90	3.69	89	8.77	101.5