Pipe Flow Rate Calculator
ANA›Life Services Authority›National Calculator Authority›Pipe Flow Rate 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; } }
Pipe Flow Rate Calculator
Calculate volumetric flow rate, average velocity, mass flow rate, and Reynolds number for fluid flow through a circular pipe.
Pipe Inner Diameter (m)
Average Flow Velocity (m/s)
Fluid Density (kg/m³)
Dynamic Viscosity (Pa·s)
Calculate Results will appear here.
function pipCalc() { const resultDiv = document.getElementById('pip-result');
const D = parseFloat(document.getElementById('pip-diameter').value); const v = parseFloat(document.getElementById('pip-velocity').value); const rho = parseFloat(document.getElementById('pip-density').value); const mu = parseFloat(document.getElementById('pip-viscosity').value);
// --- Input Validation --- if (isNaN(D) || isNaN(v) || isNaN(rho) || isNaN(mu)) { resultDiv.innerHTML = '⚠ Please fill in all fields.'; return; } if (D ⚠ Pipe diameter must be greater than zero.'; return; } if (v ⚠ Velocity cannot be negative.'; return; } if (rho ⚠ Fluid density must be greater than zero.'; return; } if (mu ⚠ Dynamic viscosity must be greater than zero.'; return; }
// --- Calculations --- // Cross-sectional area: A = π * (D/2)² const A = Math.PI * Math.pow(D / 2, 2);
// Volumetric flow rate: Q = A * v const Q = A * v;
// Mass flow rate: ṁ = ρ * Q const mDot = rho * Q;
// Reynolds number: Re = (ρ * v * D) / μ const Re = (rho * v * D) / mu;
// Flow regime let regime = ''; let regimeColor = ''; if (Re
Parameter Value
Cross-sectional Area (A) ${A.toExponential(4)} m²
Volumetric Flow Rate (Q)
${Q.toExponential(4)} m³/s ${Q_Ls.toFixed(4)} L/s | ${Q_Lmin.toFixed(3)} L/min
Mass Flow Rate (ṁ) ${mDot.toFixed(4)} kg/s
Reynolds Number (Re) ${Re.toFixed(1)}
Flow Regime ${regime}
`; }
#### Formulas Used
Cross-sectional Area: A = π × (D/2)²
Volumetric Flow Rate (Continuity Equation): Q = A × v
Mass Flow Rate: ṁ = ρ × Q
Reynolds Number: Re = (ρ × v × D) / μ
Where: D = inner diameter (m), v = average velocity (m/s), ρ = fluid density (kg/m³), μ = dynamic viscosity (Pa·s)
#### Assumptions & References
- Flow velocity entered is the average (mean) velocity across the cross-section.
- Reference: White, F.M. Fluid Mechanics, 8th ed., McGraw-Hill, 2016.
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