Pump_Sizing_Calculator.xlsx

	A	B	C	D	F	G
1	Pump Sizing & Hydraulic Power Calculator
2	chemenggcalc.com — enter values in the yellow cells; results update automatically

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4	INPUTS — Duty & Efficiency
5	Parameter	Value	Unit	Notes	Standard IEC motor sizes
6	Volumetric flow rate, Q	55.0	m³/h	Design/operating flow	kW	HP (approx)
7	Total dynamic head, H	40.0	m	Discharge + friction + static	0.3	0.3
8	Fluid density, ρ	1000	kg/m³	Water ≈ 1000	0.4	0.5
9	Gravity, g	9.81	m/s²	Constant	0.6	0.7
10	Pump efficiency, ηₚ	70	%	Typical 60–80%	0.8	1.0
11	Motor efficiency, ηₘ	92	%	Typical 90–95%	1.1	1.5
12	Motor design margin	15	%	Added before sizing motor	1.5	2.0
13					2.2	3.0
14	INPUTS — NPSH available (optional)				3.0	4.0
15	Parameter	Value	Unit	Notes	4.0	5.4
16	Suction pressure (abs), Pₛ	101.325	kPa	Atmospheric at open surface	5.5	7.4
17	Fluid vapor pressure, Pᵥ	2.339	kPa	Water @ 20°C = 2.339	7.5	10.1
18	Static suction head, hₛ	2.0	m	+ above pump / − below pump	11.0	14.8
19	Suction friction loss, hₗ	1.5	m	Pipe + fittings on suction	15.0	20.1
20					18.5	24.8
21	RESULTS				22.0	29.5
22	Parameter	Value	Unit	Formula	30.0	40.2
23	Volumetric flow rate	0.0153	m³/s	Q / 3600	37.0	49.6
24	Mass flow rate	15.28	kg/s	ρ × Q	45.0	60.3
25	Hydraulic power	6.00	kW	ρ g Q H / 1000	55.0	73.8
26	Brake / shaft power	8.56	kW	Hydraulic / ηₚ	75.0	100.6
27	Motor input power	9.31	kW	Brake / ηₘ	90.0	120.7
28	Brake power	11.48	HP	1 HP = 0.7457 kW	110.0	147.5
29	Recommended motor rating	11.0	kW	Next std IEC size above sized power	132.0	177.0
30	NPSH available	10.59	m	(Pₛ−Pᵥ)/ρg + hₛ − hₗ	160.0	214.6
31					200.0	268.2
32					250.0	335.3
33	Notes
34	• Hydraulic (water) power is the useful power delivered to the fluid; brake power is what the pump shaft must absorb.
35	• NPSH available must exceed the pump's NPSH required (from the manufacturer curve), usually with a ≥0.5 m margin, to avoid cavitation.
36	• Head H is the TOTAL dynamic head (static lift + friction + pressure head), not just the vertical rise.
37	• Recommended motor = smallest standard IEC size above the sized motor input power (motor input × design margin).
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