Men's 400 metres world record progression

The first world record in the 400 m for men (athletics) was recognized by the International Amateur Athletics Federation, now known as World Athletics, in 1912. The IAAF ratified Charles Reidpath's 48.2 s performance set at that year's Stockholm Olympics as a world record, but it also recognized the superior mark over 440 yards (402.336 metres) run by Maxie Long in 1900 as a world record.

Up to and including 2021, World Athletics has ratified 24 world records in the event.^[1]

The following tables show the world record progression in the men's 400 metres, as ratified by World Athletics.

Records 1912–1976

Time	Auto	Athlete	Nationality	Location of race	Date
47.8y		Maxie Long	United States	New York, USA	September 29, 1900[1]
48.2		Charles Reidpath	United States	Stockholm, Sweden	July 13, 1912[1]
47.4y		Ted Meredith	United States	Cambridge, USA	May 27, 1916[1][2]
47.6		Eric Liddell	United Kingdom	Paris, France	July 11, 1924[note 1][3]: 49
47.0		Emerson Spencer	United States	Palo Alto, USA	May 12, 1928[1]
46.4y		Ben Eastman	United States	Palo Alto, California, USA	March 26, 1932[1]
46.2	46.28	Bill Carr	United States	Los Angeles, USA	August 5, 1932[1]
46.1		Archie Williams	United States	Chicago, USA	June 19, 1936[1]
46.0		Rudolf Harbig	Nazi Germany	Frankfurt am Main, Nazi Germany	August 12, 1939[1]
		Grover Klemmer	United States	Philadelphia, USA	June 6, 1941[1][4]
46.0y		Herb McKenley	Jamaica	Berkeley, USA	June 5, 1948[1]
45.9	46.00	Herb McKenley	Jamaica	Milwaukee, USA	July 2, 1948[1]
45.8		George Rhoden	Jamaica	Eskilstuna, Sweden	August 22, 1950[1]
45.4A	45.68	Lou Jones	United States	Mexico City, Mexico	March 18, 1955[1]
45.2		Lou Jones	United States	Los Angeles, USA	June 30, 1956[1]
44.9	45.07	Otis Davis	United States	Rome, Italy	September 6, 1960[1]
	45.08	Carl Kaufmann	Germany	Rome, Italy	September 6, 1960[1]
44.9y		Adolph Plummer	United States	Tempe, USA	May 25, 1963[1]
44.9		Mike Larrabee	United States	Los Angeles, USA	September 12, 1964[1]
44.5+		Tommie Smith	United States	San Jose, USA	May 20, 1967[1]
44.1A	44.19	Larry James	United States	Echo Summit, USA	September 14, 1968[1]
43.8A	43.86	Lee Evans	United States	Mexico City, Mexico	October 18, 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	October 18, 1968[1]	19 years, 9 months and 30 days
43.29	Butch Reynolds	United States	Zürich, Switzerland	August 17, 1988[1]	11 years and 9 days
43.18	Michael Johnson	United States	Seville, Spain	August 26, 1999[1]	16 years, 11 months and 19 days
43.03	Wayde van Niekerk	South Africa	Rio de Janeiro, Brazil	August 14, 2016[5]	8 years, 11 months and 20 days

Excluding times run at high altitude (above 1,000 metres), the progression of automatic times is shown below.

Time	Athlete	Nationality	Location of race	Date	Duration of record
44.95	Lee Evans	United States	Winnipeg, Canada	July 30, 1967	4 years and 2 days
44.60	John Smith	United States	Cali, Colombia	August 1, 1971	4 years, 11 months and 28 days
44.26	Alberto Juantorena	Cuba	Montreal, Canada	July 29, 1976	10 years, 9 months and 4 days
44.10	Butch Reynolds	United States	Columbus, Ohio, USA	May 3, 1987	1 year, 2 months and 17 days
43.93	Butch Reynolds	United States	Indianapolis, USA	July 20, 1988	28 days
43.29	Butch Reynolds	United States	Zürich, Switzerland	August 17, 1988[1]	11 years and 9 days
43.18	Michael Johnson	United States	Seville, Spain	August 26, 1999[1]	16 years, 11 months and 19 days
43.03	Wayde van Niekerk	South Africa	Rio de Janeiro, Brazil	August 14, 2016[6]	8 years, 11 months and 20 days