Pump Efficiency Calculator
ANA›Life Services Authority›National Calculator Authority›Pump Efficiency Calculator
.calc-container { max-width: 640px; margin: 2rem 0; padding: 1.5rem; background: #fff; border: 1px solid #ddd; border-radius: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.06); font-family: system-ui, -apple-system, sans-serif; } .calc-container h3 { font-family: Georgia, serif; font-size: 1.15rem; color: #1a1a1a; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-row { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; flex-wrap: wrap; } .calc-row label { min-width: 160px; font-size: 0.9rem; color: #333; font-weight: 500; } .calc-row input[type="number"], .calc-row select { flex: 1; min-width: 120px; max-width: 200px; padding: 0.5rem 0.6rem; border: 1px solid #ccc; border-radius: 4px; font-size: 0.9rem; font-family: system-ui, sans-serif; color: #1a1a1a; background: #fafaf8; } .calc-row input:focus, .calc-row select:focus { outline: none; border-color: var(--ac, #3d5a80); box-shadow: 0 0 0 2px rgba(26,74,138,0.12); } .calc-row .unit { font-size: 0.82rem; color: #888; min-width: 30px; } .calc-btn { display: inline-block; margin-top: 0.5rem; padding: 0.55rem 1.5rem; background: var(--ac, #3d5a80); color: #fff; border: none; border-radius: 4px; font-size: 0.9rem; font-weight: 600; cursor: pointer; font-family: system-ui, sans-serif; } .calc-btn:hover { opacity: 0.9; } .calc-result { margin-top: 1.25rem; padding: 1rem 1.25rem; background: #f0f6fc; border-left: 3px solid var(--ac, #3d5a80); border-radius: 0 6px 6px 0; display: none; } .calc-result.visible { display: block; } .calc-result-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: #666; margin-bottom: 0.25rem; } .calc-result-value { font-size: 1.6rem; font-weight: 700; color: var(--ac, #3d5a80); } .calc-result-detail { font-size: 0.85rem; color: #555; margin-top: 0.5rem; line-height: 1.5; } .calc-note { margin-top: 1rem; font-size: 0.8rem; color: #888; font-style: italic; } .calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin-top: 0.75rem; } .calc-grid-item { padding: 0.6rem 0.8rem; background: #f8f9fa; border-radius: 4px; border: 1px solid #eee; } .calc-grid-item .label { font-size: 0.75rem; color: #888; text-transform: uppercase; letter-spacing: 0.04em; } .calc-grid-item .value { font-size: 1.1rem; font-weight: 600; color: #1a1a1a; } @media (max-width: 720px) { .calc-row { flex-direction: column; align-items: flex-start; gap: 0.3rem; } .calc-row label { min-width: auto; } .calc-row input[type="number"], .calc-row select { max-width: 100%; width: 100%; } .calc-grid { grid-template-columns: 1fr; } } .calc-chart { margin: 1rem 0; text-align: center; } .calc-chart svg { max-width: 100%; height: auto; } .calc-chart-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.6rem 1.2rem; margin-top: 0.6rem; font-size: 0.8rem; color: #555; } .calc-chart-legend span { display: inline-flex; align-items: center; gap: 0.3rem; } .calc-chart-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; font-style: normal; } .calc-related { max-width: 640px; margin: 2rem 0 1rem; padding: 1.25rem 1.5rem; background: #f8f9fa; border: 1px solid #e8e8e8; border-radius: 8px; } .calc-related h3 { font-family: Georgia, serif; font-size: 1rem; color: #1a1a1a; margin: 0 0 0.75rem; padding-bottom: 0.4rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-related-list { list-style: none; padding: 0; margin: 0 0 0.75rem; display: grid; grid-template-columns: 1fr 1fr; gap: 0.4rem 1.5rem; } .calc-related-list li a { font-size: 0.88rem; color: var(--ac, #3d5a80); text-decoration: none; } .calc-related-list li a:hover { text-decoration: underline; } .calc-browse-all { margin: 0.5rem 0 0; font-size: 0.9rem; font-weight: 600; } .calc-browse-all a { color: var(--ac, #3d5a80); text-decoration: none; } .calc-browse-all a:hover { text-decoration: underline; } @media (max-width: 720px) { .calc-related-list { grid-template-columns: 1fr; } }
Pump Efficiency Calculator
Calculate the overall efficiency of a pump by comparing hydraulic power delivered to the fluid against the shaft (brake) power supplied to the pump.
Volumetric Flow Rate (Q)
m³/s m³/h L/s L/min US gal/min
Total Head (H)
m (metres) ft (feet) psi bar kPa
Fluid Density (ρ)
kg/m³ lb/ft³
Water ≈ 1000 kg/m³ at 20 °C
Shaft (Brake) Power Input (Pshaft)
kW W hp (metric) hp (US)
Calculate Efficiency
function pumCalc() { var resultDiv = document.getElementById('pum-result'); resultDiv.style.display = 'none'; resultDiv.className = 'calc-result';
// --- Read inputs --- var Q_raw = parseFloat(document.getElementById('pum-flow-rate').value); var H_raw = parseFloat(document.getElementById('pum-head').value); var rho_raw = parseFloat(document.getElementById('pum-density').value); var P_raw = parseFloat(document.getElementById('pum-shaft-power').value);
var flowUnit = document.getElementById('pum-flow-unit').value; var headUnit = document.getElementById('pum-head-unit').value; var densityUnit = document.getElementById('pum-density-unit').value; var shaftUnit = document.getElementById('pum-shaft-unit').value;
// --- Validation --- var errors = []; if (isNaN(Q_raw) || Q_raw 0) { resultDiv.className = 'calc-result calc-error'; resultDiv.innerHTML = 'Please fix the following errors:' + errors.map(function(e){ return ''; }).join('') + ''; resultDiv.style.display = 'block'; return; }
// --- Unit conversions to SI (m³/s, m, kg/m³, W) --- var g = 9.80665; // m/s²
// Flow rate → m³/s var Q; if (flowUnit === 'm3s') Q = Q_raw; else if (flowUnit === 'm3h') Q = Q_raw / 3600; else if (flowUnit === 'lps') Q = Q_raw / 1000; else if (flowUnit === 'lpm') Q = Q_raw / 60000; else if (flowUnit === 'gpm') Q = Q_raw * 6.30902e-5;
// Head → metres var H; if (headUnit === 'm') H = H_raw; else if (headUnit === 'ft') H = H_raw * 0.3048; else if (headUnit === 'psi') H = H_raw * 0.703070; // psi → m of water (density-independent conversion via pressure) else if (headUnit === 'bar') H = H_raw * 1e5 / (rho_raw * g); // bar → Pa → m else if (headUnit === 'kpa') H = H_raw * 1e3 / (rho_raw * g); // kPa → Pa → m
// If psi was chosen, convert properly using actual density if (headUnit === 'psi') H = (H_raw * 6894.757) / (rho_raw * g);
// Density → kg/m³ var rho; if (densityUnit === 'kgm3') rho = rho_raw; else if (densityUnit === 'lbft3') rho = rho_raw * 16.0185;
// Shaft power → W var P_shaft; if (shaftUnit === 'kw') P_shaft = P_raw * 1000; else if (shaftUnit === 'w') P_shaft = P_raw; else if (shaftUnit === 'hp') P_shaft = P_raw * 735.49875; // metric hp else if (shaftUnit === 'hpus') P_shaft = P_raw * 745.69987; // US hp
// --- Core calculation --- // Hydraulic (water) power: P_hyd = ρ · g · Q · H [W] var P_hyd = rho * g * Q * H;
// Pump efficiency: η = P_hyd / P_shaft × 100 % var eta = (P_hyd / P_shaft) * 100;
// --- Sanity check --- if (eta > 100) { resultDiv.className = 'calc-result calc-error'; resultDiv.innerHTML = 'Result Error: Calculated efficiency exceeds 100 % (' + eta.toFixed(2) + ' %). Check your inputs — hydraulic power cannot exceed shaft power input.'; resultDiv.style.display = 'block'; return; }
// --- Rating label --- var rating, ratingColor; if (eta >= 80) { rating = 'Excellent'; ratingColor = '#2e7d32'; } else if (eta >= 65) { rating = 'Good'; ratingColor = '#558b2f'; } else if (eta >= 50) { rating = 'Fair'; ratingColor = '#f57f17'; } else { rating = 'Poor'; ratingColor = '#c62828'; }
// --- Display --- resultDiv.className = 'calc-result calc-success'; resultDiv.innerHTML = '### Results ' + '' + 'Hydraulic Power (Phyd)' + '' + (P_hyd/1000).toFixed(4) + ' kW (' + P_hyd.toFixed(2) + ' W)' + 'Shaft Power Input (Pshaft)' + '' + (P_shaft/1000).toFixed(4) + ' kW (' + P_shaft.toFixed(2) + ' W)' + 'Pump Efficiency (η)' + '' + eta.toFixed(2) + ' %' + 'Rating: ' + rating + '' + '' + '' + 'Intermediate values (SI): Q = ' + Q.toExponential(4) + ' m³/s | ' + 'H = ' + H.toFixed(4) + ' m | ρ = ' + rho.toFixed(2) + ' kg/m³';
resultDiv.style.display = 'block'; }
#### Formulas Used
Hydraulic (Water) Power:
Phyd = ρ · g · Q · H
Pump Efficiency:
η (%) = ( Phyd / Pshaft ) × 100
- Pshaft = brake power delivered to the pump shaft (W)
Pressure-based head conversion:
H = ΔP / (ρ · g)
#### Assumptions & References
- Gravitational acceleration is taken as g = 9.80665 m/s² (standard gravity, ISO 80000-3).
- The calculated efficiency is the overall (total) pump efficiency, which combines hydraulic, volumetric, and mechanical sub-efficiencies into a single figure.
- Total head (H) must represent the net head rise across the pump (discharge head minus suction head), including static lift, friction losses, and velocity head differences.
- Shaft power is the brake power measured at the pump shaft coupling, not the motor input power. Motor efficiency losses are excluded.
- Fluid is assumed to be incompressible (valid for liquids; not applicable to gases or compressible fluids).
- Typical centrifugal pump efficiencies range from 50 % (small/low-flow) to 90 % (large industrial).
- References: Hydraulic Institute Standards (ANSI/HI 1.3); Munson, Young & Okiishi, Fundamentals of Fluid Mechanics; ISO 9906 — Rotodynamic pumps: hydraulic performance acceptance tests.
More Calculators
- Home Repair Budget Calculator
- Alabama Commercial Property Lease Cost Calculator
- AI Home Device Energy Savings Calculator
- BIM vs Traditional Workflow Time Savings Calculator
- Material Cost Estimator by Room Size
- DIY vs. Contractor Cost Comparison Calculator
- Pet Age to Human Years Calculator
- SEER Rating Savings Calculator
- HVAC Financing Cost Calculator
- HVAC Replacement Cost Estimator
- HVAC Company Quote Comparison Calculator
- Air Changes Per Hour (ACH) Calculator
Read Next
Home Maintenance Annual Cost Planner ANA › Life Services Authority › National Calculator Authority › Home Maintenance Annual Cost Planner .calc-container {...
Study Time Planner Authority Network America › Life Services Authority › National Calculator Authority .calc-container { max-width: 640px;...