Date | Section of line | Broad | Mixed |
| 1 Jan 1887 | Total mileage | 184m 75c | 251m 50c |
| ? Oct 1888 | St Erth - Lelant Quay (mixed) | 1m 8c- | 1m 8c |
| 18 Jul 1891 | Creech Junction - Chard to standard gauge | 12m 61c - | |
| 31 Dec 1891 | Total mileage | 171m 6c | 252m 58c |
| All remaining broad gauge lines (i.e. lines south-west of Exeter and the mixed gauge main line between London and Exeter were converted to standard gauge on 20 - 23 May 1892) | |||
| Metric conversion: 80 chains = 1 mile; 5 miles = 8 kilometres | |||
Locomotive Class | No. (+/-) | Total | |
| 1 Jan 1887 | Total locomotives | 217 | |
| Banking 0-6-0T | - 1 | 0 | |
| Standard Goods 0-6-0 | 1 | ||
| Hawthorn 2-4-0 | - 4 | 18 | |
| Swindon 0-6-0 | -13 | 1 | |
| Sir Watkin 0-6-0T | - 4 | 2 | |
| Iron Duke Renewals (Rover) 4-2-2 | + 3 | 24 | |
| Convertible 0-6-0 | +30 | 91 | |
| Convertible 2-4-0T | +10 | 20 | |
| Convertible 0-4-2T | +19 | 19 | |
| B&ER 4-2-2 | - 4 | 0 | |
| B&ER 0-6-0 | -10 | 0 | |
| B&ER 4-2-4T | - 2 | 0 | |
| B&ER 4-4-0T | - 7 | 6 | |
| B&ER 0-6-0T | - 2 | 0 | |
| B&ER 2-4-0 | - 6 | 4 | |
| SDR 4-4-0T | 9 | ||
| SDR 0-6-0T | - 5 | 11 | |
| SDR 0-4-0T | 8 | ||
| SDR 2-4-0T | 2 | ||
| CCR 4-4-0T | - 2 | 2 | |
| TBR 0-4-0T | 1 | ||
| 31 Dec 1891 | Total locomotives | +2 | 219 |
| Key: | B&ER - Bristol & Exeter Railway (merged with GWR Jan 1876) SDR - South Devon Railway (merged with GWR Feb 1876) CCR - Carmathen & Cardigan Railway (broad gauge engines sold to SDR 1872) TBR - Torbay & Brixham Railway (merged with GWR Jan 1883) | ||
| Between Jan 1892 and Nov 1893, 127 convertible engines, 9 SDR 0-6-0T and 7 SDR 0-4-0T were altered to standard gauge. The other 76 engines were scrapped. | |||