Main Residence Nil Rate Band Calculator

Main Residence Nil Rate Band (RNRB) Calculator

Include all assets minus debts, before any reliefs.

The market value of the home being passed to direct descendants.

Enter 0 to 100 if a predeceased spouse did not use their allowance.

Calculation Results

Standard Maximum RNRB:

Tapering Reduction:

Final RNRB Allowance: £

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Understanding the Main Residence Nil Rate Band (RNRB)

The Main Residence Nil Rate Band (RNRB) is an additional Inheritance Tax (IHT) allowance introduced by the UK government to help individuals pass on their family home to direct descendants with less tax liability. As of the 2024/25 tax year, the standard RNRB is set at £175,000 per person.

How the RNRB Calculation Works

While the standard allowance is £175,000, several factors determine the actual amount your estate can claim:

• Direct Descendants: The property must be left to "direct descendants," which includes children, grandchildren, step-children, or foster children.
• Property Value Cap: The RNRB cannot exceed the actual value of the property. If your home is worth £150,000, your RNRB is capped at £150,000, even if your total allowance is higher.
• The Taper Threshold: If the total net value of the estate exceeds £2 million, the RNRB is reduced by £1 for every £2 over the threshold.
• Transferability: Like the basic Nil Rate Band, any unused RNRB can be transferred to a surviving spouse or civil partner, potentially doubling the allowance to £350,000.

Realistic Calculation Examples

Example 1: Standard Estate
Estate Value: £800,000 | Home Value: £250,000
The RNRB applied is the full £175,000 because the estate is under £2m and the home is worth more than the allowance.

Example 2: Tapered Estate
Estate Value: £2,100,000 | Home Value: £400,000
The estate is £100,000 over the taper threshold. The reduction is £50,000 (£100k / 2).
The RNRB applied is £125,000 (£175k – £50k).

Who Qualifies as a Direct Descendant?

The RNRB is strictly for transfers to direct descendants. This includes:

• Children, grandchildren, or further lineal descendants.
• Spouses or civil partners of direct descendants.
• Step-children, adopted children, and children for whom the deceased was a guardian.

It does not apply if the property is left to siblings, nephews, nieces, or other relatives who are not lineal descendants.

function calculateRNRB() { var estate = parseFloat(document.getElementById('estateValue').value) || 0; var property = parseFloat(document.getElementById('propertyValue').value) || 0; var transfer = parseFloat(document.getElementById('transferPercent').value) || 0; var baseRNRB = 175000; var taperThreshold = 2000000; // Calculate Maximum potential RNRB based on transfers var maxAvailable = baseRNRB * (1 + (transfer / 100)); // Calculate Tapering var taperReduction = 0; if (estate > taperThreshold) { taperReduction = (estate – taperThreshold) / 2; } // Apply taper to the available allowance var allowanceAfterTaper = maxAvailable – taperReduction; if (allowanceAfterTaper < 0) { allowanceAfterTaper = 0; } // RNRB is capped at the property value or the tapered allowance var finalRNRBValue = Math.min(property, allowanceAfterTaper); // Update UI document.getElementById('maxStandard').innerText = "£" + maxAvailable.toLocaleString(); document.getElementById('taperAmount').innerText = "£" + taperReduction.toLocaleString(); document.getElementById('finalRNRB').innerText = finalRNRBValue.toLocaleString(); var logicText = ""; if (property 0) { logicText = "Note: Your RNRB was reduced due to the estate value exceeding £2,000,000."; } else { logicText = "Note: You qualify for the full available RNRB based on the inputs provided."; } document.getElementById('logicNote').innerText = logicText; document.getElementById('resultArea').style.display = 'block'; }