Find your horsepower in the row, then read across. Total head is the lift from the pumping water level to the discharge, plus the pressure you want at the tank (2.31 ft for every PSI), plus friction in the drop pipe.
Total head in feet · curves end at 27.5–28.5 GPM
| HP |
0 GPM (Shut-off) |
5 GPM |
15 GPM |
22.5 GPM |
27.5 GPM |
| 1/2 HP |
173 ft |
167 ft |
122 ft |
79 ft |
24 ft |
| 3/4 HP |
233 ft |
222 ft |
170 ft |
104 ft |
33 ft |
| 1 HP |
291 ft |
281 ft |
209 ft |
130 ft |
47 ft |
| 1 1/2 HP |
383 ft |
364 ft |
279 ft |
169 ft |
57 ft |
Read from the published curve in the Pumps by Baker catalog (Sept 2025, rev 3/26), p. 46, digitized and rounded down, at the flows nearest 20%, 50% and 75% of the curve’s 28.5 GPM end. 0 GPM is the printed shut-off. For the 1/2 HP (the curve reads 186 ft at zero flow against the printed 173 ft), the printed shut-off is shown. The last column is the last flow every curve reaches; the curve ends are named in the table title.
Output in GPM at 30 PSI (switch cut-in), by depth to water
| HP |
25 ft |
50 ft |
100 ft |
150 ft |
200 ft |
250 ft |
300 ft |
| 1/2 HP |
20.00 |
16.14 |
2.99 |
— |
— |
— |
— |
| 3/4 HP |
22.98 |
20.62 |
14.94 |
5.91 |
— |
— |
— |
| 1 HP |
24.55 |
22.79 |
18.83 |
13.92 |
6.60 |
— |
— |
| 1 1/2 HP |
— |
24.78 |
22.16 |
19.20 |
15.74 |
11.35 |
4.06 |
Output in GPM at 50 PSI (switch cut-out), by depth to water
| HP |
25 ft |
50 ft |
100 ft |
150 ft |
200 ft |
250 ft |
300 ft |
| 1/2 HP |
12.08 |
4.85 |
— |
— |
— |
— |
— |
| 3/4 HP |
18.40 |
15.44 |
6.92 |
— |
— |
— |
— |
| 1 HP |
21.19 |
19.15 |
14.34 |
7.36 |
— |
— |
— |
| 1 1/2 HP |
— |
22.37 |
19.44 |
16.03 |
11.73 |
4.93 |
— |
Output tables as printed in the Pumps by Baker catalog (Sept 2025, rev 3/26), pp. 45-46, at the 30 and 50 PSI rows. Riser-pipe friction is not included (manufacturer note): add it for long or small drop pipe. — marks a point A.Y. McDonald does not print for that horsepower.
Best operating range: the published curve shades the most efficient operating range for each model; the catalog prints no figures for it. The curve is in the image gallery.