M40 motorway
mile km Southbound exits (B carriageway) Junction Northbound exits (A carriageway) Coordinates
18.1 29.2 End of motorway
Road continues as A40 to London
J1
Start of motorway
Road formed from main carriageways of A40 from London
51°33′41″N 0°29′45″W / 51.561305°N 0.495887°W / 51.561305; -0.495887 (M40, J1)
Slough A412
Uxbridge A4020
Non motorway traffic
19.9
20.4
32.0
32.9
Watford (M1) Heathrow Airport (M4) (M3, M23, M11) M25 J1a Watford &(M1) Stansted Airport (M11) Heathrow Airport (M4)
Gatwick Airport (M23) M25
51°33′39″N 0°31′53″W / 51.560798°N 0.531335°W / 51.560798; -0.531335 (M40, J1A)
24.8
25.3
39.9
40.7
Beaconsfield, Amersham, Slough A355, Beaconsfield services J2
Services
Beaconsfield, Amersham, Slough A355, Beaconsfield services 51°35′39″N 0°37′39″W / 51.594295°N 0.627637°W / 51.594295; -0.627637 (M40, J2)
27.8
28.1
44.7
45.2
No access J3 Loudwater and High Wycombe (East) A40 51°36′12″N 0°41′30″W / 51.603359°N 0.691710°W / 51.603359; -0.691710 (M40, J3)
31.3
31.6
50.3
50.9
High Wycombe, Marlow, Maidenhead A404 (M4)+ J4 High Wycombe, Marlow A404 (M4) 51°36′44″N 0°46′07″W / 51.612261°N 0.768485°W / 51.612261; -0.768485 (M40, J4)
38.9
39.3
62.6
63.2
High Wycombe (West), Stokenchurch A40 J5 Stokenchurch A40 51°39′38″N 0°54′46″W / 51.660524°N 0.912895°W / 51.660524; -0.912895 (M40, J5)
41.4
41.8
66.7
67.2
Watlington, Princes Risborough B4009 J6 Thame, Watlington, Princes Risborough B4009 51°40′20″N 0°57′38″W / 51.672236°N 0.96066°W / 51.672236; -0.96066 (M40, J6)
47.0
75.6
75.6
76.2
No access J7 Thame, Wallingford, A329 51°43′28″N 1°03′27″W / 51.724583°N 1.057477°W / 51.724583; -1.057477 (M40, J7)
48.0
48.4
77.3
77.9
No access J8 Oxford, Cheltenham A40 51°43′56″N 1°04′37″W / 51.732291°N 1.076832°W / 51.732291; -1.076832 (M40, J8)
49.0
49.2
78.9
79.2
Thame, Aylesbury A418
Oxford (A40), Oxford services
J8a
Services
Thame, Aylesbury A418
Oxford (A40), Oxford services
51°44′24″N 1°05′44″W / 51.740052°N 1.095457°W / 51.740052; -1.095457 (M40, J8a)
60.3
60.6
97.1
97.6
Bicester, Aylesbury A41
Oxford, Newbury A34
J9 Bicester A41
Oxford, Newbury A34
51°52′08″N 1°11′54″W / 51.868754°N 1.198454°W / 51.868754; -1.198454 (M40, J9)
65.9
66.2
106.0
106.6
Northampton A43 (M1)
B430, Cherwell Valley services
J10
Services
Northampton A43 (M1)
B430, Cherwell Valley services
51°56′59″N 1°12′22″W / 51.949635°N 1.206093°W / 51.949635; -1.206093 (M40, J10)
76.2
76.7
122.7
123.4
Banbury A422
Daventry A361
J11 Banbury A422
Chipping Norton A361
52°04′22″N 1°18′48″W / 52.072675°N 1.313295°W / 52.072675; -1.313295 (M40, J11)
86.8
87.0
139.7
140.0
Gaydon B4451 J12 Gaydon B4451 52°11′32″N 1°27′29″W / 52.192219°N 1.458135°W / 52.192219; -1.458135 (M40, J12)
89.8 144.5 Warwick Services Services Warwick Services 52°13′05″N 1°30′15″W / 52.218125°N 1.504269°W / 52.218125; -1.504269 (M40, Warwick Services)
92.1
92.3
148.2
148.6
No access J13 Leamington, Warwick A452
B4100
52°14′26″N 1°33′13″W / 52.240678°N 1.553578°W / 52.240678; -1.553578 (M40, J13)
93.9
94.2
151.1
151.6
Leamington A452 J14 No access 52°15′25″N 1°35′18″W / 52.256863°N 1.588211°W / 52.256863; -1.588211 (M40, J14)
95.0
95.3
152.9
153.4
Warwick A429
Stratford, Coventry A46 Leicester (M69)
J15 Warwick A429
Stratford, Coventry A46 Leicester (M69)
52°15′36″N 1°36′48″W / 52.260068°N 1.613359°W / 52.260068; -1.613359 (M40, J15)
103.8
104.1
167.1
167.6
Henley A3400 J16 No access 52°20′06″N 1°46′28″W / 52.335129°N 1.774549°W / 52.335129; -1.774549 (M40, J16)
105.7
106.0
170.1
170.6
Start of motorway
Motorway is formed by two sliproads from the M42
J17
(M42, J3a)
End of motorway
Road continues as M42
The SOUTH WEST, Birmingham (South & West), Redditch & M5
The North, Birmingham (North, East) M1, M6
52°20′51″N 1°49′09″W / 52.347367°N 1.819139°W / 52.347367; -1.819139 (M40, End of motorway)