SEER / EER Rating Calculator
ANA›Life Services Authority›National Calculator Authority›SEER / EER Rating 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; } }
SEER / EER Rating Calculator
Calculate the Seasonal Energy Efficiency Ratio (SEER) and Energy Efficiency Ratio (EER) for air conditioning and heat pump systems. Convert between SEER and EER, or compute ratings from cooling output and power input.
### Mode 1 — Compute SEER & EER from System Data
Cooling Capacity (BTU/hr)
Power Input (Watts)
Seasonal Operating Hours
Seasonal Energy Consumed (kWh)
### Mode 2 — Convert Between SEER and EER
Known SEER Rating
Known EER Rating
Calculate
function seeCalc() { const resultDiv = document.getElementById('see-result'); resultDiv.style.display = 'none'; resultDiv.innerHTML = '';
// --- Read inputs --- const coolingBtu = parseFloat(document.getElementById('see-cooling-btu').value); const powerWatts = parseFloat(document.getElementById('see-power-watts').value); const seasonHours = parseFloat(document.getElementById('see-seasonal-hours').value); const seasonKwh = parseFloat(document.getElementById('see-seasonal-kwh').value); const seerInput = parseFloat(document.getElementById('see-seer-input').value); const eerInput = parseFloat(document.getElementById('see-eer-input').value);
let lines = []; let hasResult = false;
// ------------------------------------------------------- // MODE 1A: EER from cooling capacity + power input // EER = BTU/hr ÷ Watts // ------------------------------------------------------- if (!isNaN(coolingBtu) && !isNaN(powerWatts)) { if (coolingBtu '); lines.push('SEER (from seasonal data):'); lines.push('Total Seasonal BTU = ' + coolingBtu.toLocaleString() + ' × ' + seasonHours.toLocaleString() + ' = ' + totalBtu.toLocaleString() + ' BTU'); lines.push('Total Seasonal Wh = ' + seasonKwh.toLocaleString() + ' kWh × 1000 = ' + totalWh.toLocaleString() + ' Wh'); lines.push('SEER = ' + totalBtu.toLocaleString() + ' ÷ ' + totalWh.toLocaleString() + ' = ' + seer.toFixed(2) + ''); lines.push(ratingLabel('SEER', seer));
hasResult = true; }
// ------------------------------------------------------- // MODE 2A: SEER → EER conversion // EER ≈ SEER × 0.875 (AHRI Standard 210/240) // ------------------------------------------------------- if (!isNaN(seerInput)) { if (seerInput '); lines.push('Convert SEER → EER:'); lines.push('EER ≈ SEER × 0.875 = ' + seerInput.toFixed(2) + ' × 0.875 = ' + eerFromSeer.toFixed(2) + ''); lines.push(ratingLabel('SEER', seerInput)); lines.push(ratingLabel('EER', eerFromSeer));
// Annual energy cost estimate (2000 hrs, 12,000 BTU/hr = 1 ton baseline) const annualKwh = (12000 * 2000) / (seerInput * 1000); lines.push(''); lines.push('Estimated annual energy use (1-ton unit, 2,000 hrs/yr): ' + annualKwh.toFixed(0) + ' kWh');
hasResult = true; }
// ------------------------------------------------------- // MODE 2B: EER → SEER conversion // SEER ≈ EER ÷ 0.875 // ------------------------------------------------------- if (!isNaN(eerInput)) { if (eerInput '); lines.push('Convert EER → SEER:'); lines.push('SEER ≈ EER ÷ 0.875 = ' + eerInput.toFixed(2) + ' ÷ 0.875 = ' + seerFromEer2.toFixed(2) + ''); lines.push(ratingLabel('EER', eerInput)); lines.push(ratingLabel('SEER', seerFromEer2));
hasResult = true; }
if (!hasResult) { showError('Please enter at least one set of values (cooling capacity + power, or a SEER/EER value).'); return; }
resultDiv.innerHTML = lines.join(''); resultDiv.style.display = 'block';
// --- Helpers --- function showError(msg) { resultDiv.innerHTML = '⚠ ' + msg + ''; resultDiv.style.display = 'block'; }
function seerToEer(seer) { return seer * 0.875; } function eerToSeer(eer) { return eer / 0.875; }
function ratingLabel(type, val) { let label = '', color = '#27ae60'; if (type === 'SEER') { if (val >= 21) { label = '★ Excellent (ENERGY STAR Most Efficient)'; color = '#1a7a4a'; } else if (val >= 18) { label = '★ Very Good (ENERGY STAR)'; color = '#27ae60'; } else if (val >= 15) { label = '★ Good (above federal minimum)'; color = '#2980b9'; } else if (val >= 13) { label = '△ Meets federal minimum (2023 standard)'; color = '#e67e22'; } else { label = '▼ Below current federal minimum'; color = '#c0392b'; } } else { if (val >= 14) { label = '★ Excellent'; color = '#1a7a4a'; } else if (val >= 12) { label = '★ Good'; color = '#27ae60'; } else if (val >= 10) { label = '△ Average'; color = '#e67e22'; } else { label = '▼ Below average'; color = '#c0392b'; } } return '' + type + ' ' + val.toFixed(2) + ' — ' + label + ''; } }
#### Formulas
EER (Energy Efficiency Ratio) EER = Cooling Output (BTU/hr) ÷ Power Input (Watts) Measured at a single steady-state condition: 95°F outdoor / 80°F indoor / 50% RH.
SEER (Seasonal Energy Efficiency Ratio) SEER = Total Seasonal Cooling Output (BTU) ÷ Total Seasonal Energy Input (Wh) = [BTU/hr × Operating Hours] ÷ [kWh × 1,000] Represents performance across a full cooling season with varying temperatures.
SEER ↔ EER Conversion (AHRI 210/240 approximation) EER ≈ SEER × 0.875 SEER ≈ EER ÷ 0.875 The factor 0.875 accounts for part-load operation and seasonal temperature variation.
Cooling Capacity in Tons Tons = BTU/hr ÷ 12,000
#### Assumptions & References
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