NI Class 2 vs Class 4 Contributions Comparator
ANA›Life Services Authority›National Calculator Authority›NI Class 2 vs Class 4 Contributions Comparator
.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; } }
NI Class 2 vs Class 4 Contributions Comparator
Compare your Class 2 and Class 4 National Insurance contributions as a self-employed individual based on your annual profit. Uses 2024/25 HMRC rates.
Annual Profit (£)
Tax Year
2024/25 2023/24
Calculate
### Results
Contribution Type Amount (£) Rate / Notes
Class 2 NI — —
Class 4 NI (Lower Band) — —
Class 4 NI (Upper Band) — —
Total Class 4 NI — —
Total NI Liability — —
function niCalc() { var errorEl = document.getElementById('ni-error'); var resultEl = document.getElementById('ni-result'); errorEl.style.display = 'none'; resultEl.style.display = 'none';
var profitRaw = document.getElementById('ni-profit').value.trim(); var taxYear = document.getElementById('ni-tax-year').value;
// Validation if (profitRaw === '') { errorEl.textContent = 'Please enter your annual profit.'; errorEl.style.display = 'block'; return; } var profit = parseFloat(profitRaw); if (isNaN(profit) || profit 10000000) { errorEl.textContent = 'Please enter a realistic profit figure (up to £10,000,000).'; errorEl.style.display = 'block'; return; }
// HMRC rates by tax year // 2024/25: Class 2 = £3.45/week (if profit >= SPT £6,725); Class 4: 6% on £12,570–£50,270, 2% above £50,270 // 2023/24: Class 2 = £3.45/week (if profit >= SPT £12,570); Class 4: 9% on £12,570–£50,270, 2% above £50,270 // Note: From April 2024, Class 2 is effectively abolished for most; those with profits >= LPL get NI credit without paying. // The model treats 2024/25 as: Class 2 = £0 if profit >= SPT (treated as credit, no charge), but show the old rate for comparison. // For clarity we show the actual liability.
var rates = {}; if (taxYear === '2425') { rates = { label: '2024/25', class2WeeklyRate: 3.45, class2SPT: 6725, // Small Profits Threshold class2LPL: 12570, // Lower Profits Limit (above this, Class 2 is treated as paid, no charge) class2Abolished: true, // From April 2024, Class 2 is effectively £0 for profits >= LPL class4LPL: 12570, // Lower Profits Limit class4UPL: 50270, // Upper Profits Limit class4LowerRate: 0.06, // 6% between LPL and UPL class4UpperRate: 0.02 // 2% above UPL }; } else { rates = { label: '2023/24', class2WeeklyRate: 3.45, class2SPT: 12570, class2LPL: 12570, class2Abolished: false, class4LPL: 12570, class4UPL: 50270, class4LowerRate: 0.09, // 9% between LPL and UPL class4UpperRate: 0.02 // 2% above UPL }; }
var weeksInYear = 52;
// Class 2 Calculation var class2Amount = 0; var class2Note = ''; if (taxYear === '2425') { if (profit = SPT get NI credit at no cost class2Amount = 0; class2Note = 'Treated as paid (no charge from Apr 2024)'; } } else { if (profit rates.class4LPL) { var lowerBandProfit = Math.min(profit, rates.class4UPL) - rates.class4LPL; class4Lower = lowerBandProfit * rates.class4LowerRate; } if (profit > rates.class4UPL) { var upperBandProfit = profit - rates.class4UPL; class4Upper = upperBandProfit * rates.class4UpperRate; }
var class4Total = class4Lower + class4Upper; var totalNI = class2Amount + class4Total; var effectiveRate = profit > 0 ? (totalNI / profit) * 100 : 0;
// Lower band note var lowerNote = ''; if (profit
#### Formulas Used
Class 2 NI (2023/24): If profit ≥ Small Profits Threshold (SPT): Class 2 = Weekly Rate × 52 If profit < SPT: Class 2 = £0 (voluntary contributions only)
Class 2 NI (2024/25): Effectively abolished — self-employed with profits ≥ SPT receive NI credit at no cost.
Class 4 NI: Lower Band = (min(Profit, UPL) − LPL) × Lower Rate [if Profit > LPL] Upper Band = (Profit − UPL) × Upper Rate [if Profit > UPL] Total Class 4 = Lower Band + Upper Band
Total NI = Class 2 + Total Class 4 Effective Rate = Total NI ÷ Profit × 100
Parameter 2023/24 2024/25
Class 2 Weekly Rate£3.45£0 (abolished) Small Profits Threshold (SPT)£12,570£6,725 Lower Profits Limit (LPL)£12,570£12,570 Upper Profits Limit (UPL)£50,270£50,270 Class 4 Lower Rate9%6% Class 4 Upper Rate2%2%
#### Assumptions & References
- References: HMRC — Self-employed National Insurance rates; Spring Budget 2024; Autumn Statement 2023.
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