Men's 400 metres world record progression

Records 1912–1976

Time	Auto	Athlete	Nationality	Location of race	Date
47.8y		Maxie Long	United States	New York, USA	29 September 1900[1]
48.2		Charles Reidpath	United States	Stockholm, Sweden	13 July 1912[1]
47.4y		Ted Meredith	United States	Cambridge, USA	27 May 1916[1][3]
47.6		Eric Liddell	United Kingdom	Paris, France	11 July 1924[note 1][4]: 49
47.0		Emerson Spencer	United States	Palo Alto, USA	12 May 1928[1]
46.4y		Ben Eastman	United States	Palo Alto, California, USA	26 March 1932[1]
46.2	46.28	Bill Carr	United States	Los Angeles, USA	5 August 1932[1]
46.1		Archie Williams	United States	Chicago, USA	19 June 1936[1]
46.0		Rudolf Harbig	Germany	Frankfurt am Main, Germany	12 August 1939[1]
		Grover Klemmer	United States	Philadelphia, USA	6 June 1941[1][5]
46.0y		Herb McKenley	Jamaica	Berkeley, USA	5 June 1948[1]
45.9	46.00	Herb McKenley	Jamaica	Milwaukee, USA	2 July 1948[1]
45.8		George Rhoden	Jamaica	Eskilstuna, Sweden	22 August 1950[1]
45.4 A	45.68	Lou Jones	United States	Mexico City, Mexico	18 March 1955[1]
45.2		Lou Jones	United States	Los Angeles, USA	30 June 1956[1]
44.9	45.07	Otis Davis	United States	Rome, Italy	6 September 1960[1]
	45.08	Carl Kaufmann	Germany	Rome, Italy	6 September 1960[1]
44.9y		Adolph Plummer	United States	Tempe, USA	25 May 1963[1]
44.9		Mike Larrabee	United States	Los Angeles, USA	12 September 1964[1]
44.5+		Tommie Smith	United States	San Jose, USA	20 May 1967[1]
44.1 A	44.19	Larry James	United States	Echo Summit, USA	14 September 1968[1]
43.8 A	43.86	Lee Evans	United States	Mexico City, Mexico	18 October 1968[1]

(+) plus sign denotes en route time during longer race
"y" denotes time for 440 yards, ratified as a record for this event
"A" indicates that the time was set at altitude.

The "Time" column indicates the ratified mark; the "Auto" column indicates a fully automatic time that was also recorded in the event when hand-timed marks were used for official records, or which was the basis for the official mark, rounded to the 10th of a second, depending on the rules then in place.

Records post-1976

From 1975, the IAAF accepted separate automatically electronically timed records for events up to 400 metres. Starting January 1, 1977, the IAAF required fully automatic timing to the hundredth of a second for these events.^[1]

Lee Evans' 1968 Olympic gold medal victory time of 43.86 was the fastest recorded result to that time.

Time	Athlete	Nationality	Location of race	Date	Duration of record
43.86 A	Lee Evans	United States	Mexico City, Mexico	18 October 1968[1]	19 years, 9 months and 30 days
43.29	Butch Reynolds	United States	Zürich, Switzerland	17 August 1988[1]	11 years and 9 days
43.18	Michael Johnson	United States	Seville, Spain	26 August 1999[1]	16 years, 11 months and 19 days
43.03	Wayde van Niekerk	South Africa	Rio de Janeiro, Brazil	14 August 2016[6]	9 years, 10 months and 17 days

For the period when the record automatic time was Lee Evans' mark of 43.86, the progression excluding races run at high altitude (above 1,000 metres) was as follows:

Time	Athlete	Nationality	Location of race	Date	Duration of record
44.95	Lee Evans	United States	Winnipeg, Canada	30 July 1967	4 years and 2 days
44.60	John Smith	United States	Cali, Colombia[7]	1 August 1971	4 years, 11 months and 28 days
44.26	Alberto Juantorena	Cuba	Montreal, Canada	29 July 1976	10 years, 9 months and 4 days
44.10	Butch Reynolds	United States	Columbus, Ohio, USA	3 May 1987	1 year, 2 months and 17 days
43.93	Butch Reynolds	United States	Indianapolis, USA	20 July 1988	28 days