information:classification, structural:summarization
Attrition statistics

Overall, by 2 November, the RAF fielded 1,796 pilots, an increase of over 40% from July 1940's count of 1,259 pilots. Based on German sources (from a Luftwaffe intelligence officer Otto Bechtle attached to KG 2 in February 1944) translated by the Air Historical Branch, Stephen Bungay asserts German fighter and bomber "strength" declined without recovery, and that from August–December 1940, the German fighter and bomber strength declined by 30 and 25 per cent. In contrast, Williamson Murray argues (using translations by the Air Historical Branch) that 1,380 German bombers were on strength on 29 June 1940, 1,420 bombers on 28 September, 1,423 level bombers on 2 November and 1,393 bombers on 30 November 1940. In July–September the number of Luftwaffe pilots available fell by 136, but the number of operational pilots had shrunk by 171 by September. The training organisation of the Luftwaffe was failing to replace losses. German fighter pilots, in contrast to popular perception, were not afforded training or rest rotations, unlike their British counterparts. The first week of September accounted for 25% of Fighter Command's and 24% of the Luftwaffe's overall losses. Between the dates 26 August – 6 September, on only one day (1 September) did the Germans destroy more aircraft than they lost. Losses were 325 German and 248 British.

Luftwaffe losses for August numbered 774 aircraft to all causes, representing 18.5% of all combat aircraft at the beginning of the month. Fighter Command's losses in August were 426 fighters destroyed, amounting to 40 per cent of 1,061 fighters available on 3 August. In addition, 99 German bombers and 27 other types were destroyed between 1 and 29 August.

From July to September, the Luftwaffe's loss records indicate the loss of 1,636 aircraft, 1,184 to enemy action. This represented 47% of the initial strength of single-engined fighters, 66% of twin-engined fighters, and 45% of bombers. This indicates the Germans were running out of aircrew as well as aircraft.

Throughout the battle, the Germans greatly underestimated the size of the RAF and the scale of British aircraft production. Across the Channel, the Air Intelligence division of the Air Ministry consistently overestimated the size of the German air enemy and the productive capacity of the German aviation industry. As the battle was fought, both sides exaggerated the losses inflicted on the other by an equally large margin. The intelligence picture formed before the battle encouraged the Luftwaffe to believe that such losses pushed Fighter Command to the very edge of defeat, while the exaggerated picture of German air strength persuaded the RAF that the threat it faced was larger and more dangerous than was the case. This led the British to the conclusion that another fortnight of attacks on airfields might force Fighter Command to withdraw their squadrons from the south of England. The German misconception, on the other hand, encouraged first complacency, then strategic misjudgement. The shift of targets from air bases to industry and communications was taken because it was assumed that Fighter Command was virtually eliminated.

Between 24 August and 4 September, German serviceability rates, which were acceptable at Stuka units, were running at 75% with Bf 109s, 70% with bombers and 65% with Bf 110s, indicating a shortage of spare parts. All units were well below established strength. The attrition was beginning to affect the fighters in particular. By 14 September, the Luftwaffe's Bf 109 Geschwader possessed only 67% of their operational crews against authorised aircraft. For Bf 110 units it was 46 per cent; and for bombers it was 59 per cent. A week later the figures had dropped to 64 per cent, 52% and 52 per cent. Serviceability rates in Fighter Command's fighter squadrons, between 24 August and 7 September, were listed as: 64.8% on 24 August; 64.7% on 31 August and 64.25% on 7 September 1940.

Due to the failure of the Luftwaffe to establish air supremacy, a conference assembled on 14 September at Hitler's headquarters. Hitler concluded that air superiority had not yet been established and "promised to review the situation on 17 September for possible landings on 27 September or 8 October. Three days later, when the evidence was clear that the German Air Force had greatly exaggerated the extent of their successes against the RAF, Hitler postponed Sea Lion indefinitely."