Nationwide ISA Calculator
See how much interest you could earn with a Nationwide ISA.
Investment ISAs put your capital at risk & you may get back less than you originally invested
- Term: Instant Access
- Invest From: £100
Interest paid annually. Unlimited deposits and withdrawals. ISA transfers also allowed in (some providers charge a transfer fee). Open and manage online. FSCS Protected.. Must be UK resident and be aged 18 or older. After 12 months the interest rate changes to 1.45% AER variable. Online ISA is provided by OneFamily, savings in Post Office Cash ISAs are deposited with Bank of Ireland UK
- Term: Easy Access
- Invest From: £1,000
Interest paid annually. Unlimited deposits and withdrawals. ISA transfers also allowed in. Open and manage online. FSCS Protected. Must be UK resident and be aged 18 or older
- Term: Easy Access (up to 4 withdrawals per year)
- Invest From: £1
Withdraw on any 4 days a year. Interest paid at maturity. Unlimited deposits. ISA transfers in also allowed. Open and manage your account online. FSCS Protected. Must be UK resident and be aged 18 or older. After 12 months, the account will be transferred to an online easy access cash ISA account
- Term: Instant Access
- Invest From: £1
Unlimited deposits and withdrawals. Interest paid monthly. ISA transfers also allowed. Open and manage online or in app
FSCS Protected. £500,000 maximum deposit across all OakNorth accounts. Must be UK resident and aged 18 or older
- Term: Instant Access
- Invest From: £1,000
3.35% AER / 3.30% tax-free p.a (variable), interest paid monthly. Flexible ISA – withdraw and replace funds without affecting your annual ISA allowance. Unlimited deposits and withdrawals. Interest paid monthly. ISA transfers also allowed in. FSCS Protected. Tax treatments depend on your individual circumstances and may change in the future’. Powered by ClearBank: Wealthify will provide the day-to-day servicing of the account with ClearBank providing the account itself. Must be UK resident and be aged 18 or older
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- Term: Instant Access for 12 months
- Invest From: £500
Interest paid annually. Unlimited deposits and withdrawals. ISA transfers also allowed in. Manage your account in branch, online using internet or mobile, or over the phone. FSCS Protected. Must be UK resident and be aged 18 or older. After 12 months, Santander will transfer your account to an ISA Saver. Before the term ends, Santander will contact you with your new interest rate.
- Term: 1 Year
- Invest From: £25,000
Terms and Conditions: 4.20% AER/Tax-free p.a. (fixed) for 1 year on balances above £25,000. Alternative rates available on balances below £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
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- Term: 1 Year
- Invest From: £25,000
Terms and Conditions: 4.20% AER/Tax-free p.a. (fixed) for 1 year on balances above £25,000. Alternative rates available on balances below £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
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- Term: 1 Year
- Invest From: £1,000
Interest paid annually. ISA transfers not currently allowed in. Open and manage online. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 90 days lost interest
- Term: 1 Year
- Invest From: £1,000
Terms and Conditions: 4.05% AER/Tax-free p.a. (fixed) for 1 year on balances between £1,000 – £24,999. Alternative rates available on balances above £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
Show More- Term: 1 Year
- Invest From: £1,000
Terms and Conditions: 4.050% AER/Tax-free p.a. (fixed) for 1 year on balances between £1,000 – £24,999. Alternative rates available on balances above £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
Show More- Term: 1 Year
- Invest From: £500
Interest paid at maturity. ISA transfers also allowed in. Manage your account in branch, online using internet or mobile, or over the phone. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 120 days lost interest.
- Term: 1 Year
- Invest From: £1
Interest paid at maturity. ISA transfers also allowed in. Maximum deposit £250,000. FSCS Protected. Winner of Platinum Feefo Trusted Service Award in 2024. Must be UK resident and be aged 18 or older. No withdrawals permitted
- Term: 12 Months
- Invest From: £1
Interest paid monthly. ISA transfers also allowed in. Maximum balance £500,000. FSCS Protected. Must be UK resident and be aged 18 or older. 90-day interest penalty on early withdrawals
- Term: 1 Year
- Invest From: £100
Interest paid annually. ISA transfers also allowed in. Open online, in branch or by post. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 90 days lost interest
- Term: 1 Year
- Invest From: £500
Interest paid annually. ISA transfers also allowed in (some providers charge a transfer fee). Open and manage online. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 90 days loss of interest. Online ISA is provided by OneFamily, savings in Post Office Cash ISAs are deposited with Bank of Ireland UK
- Term: 2 Years
- Invest From: £25,000
Terms and Conditions: 4.30% AER/Tax-free p.a. (fixed) for 2 years on balances above £25,000. Alternative rates available on balances below £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
Show More- Term: 2 Years
- Invest From: £25,000
Terms and Conditions: 4.30% AER/Tax-free p.a. (fixed) for 2 years on balances above £25,000. Alternative rates available on balances below £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
Show More- Term: 2 Years
- Invest From: £1,000
Terms and Conditions: 4.05% AER/Tax-free p.a. (fixed) for 2 years on balances between £1,000 – £24,999. Alternative rates available on balances above £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
Show More- Term: 2 Years
- Invest From: £1,000
Terms and Conditions: 4.05% AER/Tax-free p.a. (fixed) for 2 years on balances between £1,000 – £24,999. Alternative rates available on balances above £25,000. Rate available until 5pm on 15th April 2026 for new customers and 20th April 2026 for existing customers. Offer may be withdrawn early due to limited availability. Interest is calculated daily and paid at maturity. You can withdraw money from your account up to 11th May 2026. If you want to make a withdrawal after this time and before the Maturity Date, you must close your account by giving written notice in branch. If you make a payment into your Fixed Rate ISA you will not be able to make any further payments for that tax year into any other cash ISA with NatWest or Royal Bank of Scotland. Early Closure Charge applies: the lower of the amount of interest earned on your account or 90 days’ interest. The Early Closure Charge will be deducted from your Fixed Rate ISA. Must be 18+ and UK resident
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- Term: 2 Years
- Invest From: £1000
Interest paid monthly or annually. ISA transfers in up to a maximum account balance of £1,000,000. FSCS Protected. Must be UK resident and be aged 18 or older. 180 day interest charge on early withdrawals
- Term: 2 Years
- Invest From: £500
Interest paid annually. ISA transfers also allowed in. Manage your account in branch, online using internet or mobile, or over the phone. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 120 days lost interest.
- Term: 2 Years
- Invest From: £1
Interest paid annually. ISA transfers also allowed in. Maximum deposit £250,000. FSCS Protected. Winner of Platinum Feefo Trusted Service Award in 2024. Must be UK resident and be aged 18 or older. No withdrawals permitted
- Term: 2 Years
- Invest From: £100
Interest paid annually. ISA transfers also allowed in. Open online, in branch or by post. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 180 days lost interest
- Term: 2 Years
- Invest From: £100
Interest paid annually. ISA transfers also allowed in. Tax free interest. FSCS Protected. Must be UK resident and be aged 18 or older. No withdrawals permitted. Closure permitted with 270 days’ loss of interest
- Term: 2 Years
- Invest From: £500
Interest paid annually. ISA transfers also allowed in (some providers charge a transfer fee). Open and manage online. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 180 days loss of interest. Online ISA is provided by OneFamily, savings in Post Office Cash ISAs are deposited with Bank of Ireland UK
- Term: 24 Months
- Invest From: £1
Interest paid monthly. ISA transfers also allowed in. Maximum balance £500,000. FSCS Protected. Must be UK resident and be aged 18 or older. 180 day interest penalty on early withdrawals
- Term: 3 Years
- Invest From: £100
Interest paid annually. ISA transfers also allowed in. Open online, in branch or by post. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 270 days lost interest
- Term: 3 Years
- Invest From: £1
Interest paid annually. ISA transfers also allowed in. Maximum deposit £250,000. FSCS Protected. Winner of Platinum Feefo Trusted Service Award in 2021. Must be UK resident and be aged 18 or older. No withdrawals permitted
- Term: 36 Months
- Invest From: £1
Interest paid monthly. ISA transfers also allowed in. Maximum balance £500,000. FSCS Protected. Must be UK resident and be aged 18 or older. 270 day interest penalty on early withdrawals
- Term: 5 Years
- Invest From: £100
Interest paid annually. ISA transfers also allowed in. Open online, in branch or by post. FSCS Protected. Must be UK resident and be aged 18 or older. Withdrawals permitted subject to 365 days lost interest
- Term: 5 Years
- Invest From: £1
Interest paid annually. ISA transfers also allowed in. Maximum deposit £250,000. FSCS Protected. Winner of Platinum Feefo Trusted Service Award in 2024. Must be UK resident and be aged 18 or older. No withdrawals permitted
- Term: 5 Years
- Invest From: £100
Interest paid annually. ISA transfers also allowed in. Tax free interest. FSCS Protected. Must be UK resident and be aged 18 or older. No withdrawals permitted. Closure permitted with 360 days’ loss of interest
Try our free ISA calculator
Click here for our free ISA Calculator »
Using our free ISA interest calculator, you can see how much you could grow your savings with a Nationwide ISA.
The calculator shows how much interest you might earn with different ISAs, based on how much you deposit, the interest rate offered and how long you want to save for.
This provides valuable guidance when deciding how to use your tax-free ISA allowance, which for the 2017/18 tax year is £20,000 (or £4,128 for a Junior ISA).
Compare Nationwide ISA deals
Nationwide is one of a number of different ISA providers, so to make sure you are getting the best deal with your savings it is sensible to compare as many different ISA products as possible. Our free ISA interest calculator makes this as simple as possible.
The calculator lets you see the effect of three different factors:
- Amount saved
- Interest rate earned
- Length of time saved for
This allows you to see how much you will need to deposit into different ISAs to achieve a specific savings goal, or how much you could generate based on the amount you want to deposit each month.
How does our ISA calculator work?
Our calculator gives an estimate of the total growth you may achieve based on the figures you provide. This estimate is for guidance purposes only and the actual amount of growth you see will depend on how interest rates change over time.
Our estimate assumes the following:
- You will deposit money into your account on a regular basis
- There will be no withdrawals made
- The market will stay broadly steady
- Interest rates will remain productive
- There will be no reduction in the ISA tax-free savings allowance during the term of your account
See how much interest you could earn with a Nationwide ISA
Thinking about taking out a Nationwide ISA? Find out how much you might be able to earn in interest now with our free ISA interest calculator.
Click here for our free ISA Calculator »