Set your deposit target and see exactly how long it will take to reach it at your monthly contribution level. The calculator shows target deposit, remaining amount, and months and years required, with interest applied at the default 4.5% AER. Adjust the inputs to model different deposit percentages, monthly contributions, and savings rates.

How the calculator works

The calculator runs a month-by-month compounding model:

1. Calculate target deposit = property price × deposit percentage.
2. Calculate remaining = target − current savings.
3. For each future month, apply monthly interest (rate/12) to running balance, then add monthly contribution.
4. If LISA bonus is enabled, add 25% bonus on annual contribution up to £4,000/year.
5. Stop when balance ≥ target. Report months elapsed.

This gives a more accurate answer than simple division because of compounding. At 4.5% AER over 4 years, compounding adds ~£900 to a £24,000 savings pot — about a month's contribution.

Worked example 1 — 10% deposit on £250,000

Target: £25,000. Current savings: £5,000. Monthly contribution: £500. Rate: 4.5% AER.

Result: 3 years 2 months. Without compound interest, simple division gives 3 years 4 months (£20,000 ÷ £500/mo = 40 months). Compounding saves 2 months.

Worked example 2 — 15% deposit on £350,000

Target: £52,500. Current savings: £10,000. Monthly contribution: £700. Rate: 4.5% AER.

Result: 4 years 6 months. Compounding adds £4,800 of free interest over the period.

Worked example 3 — 10% deposit on £350,000 with LISA

Target: £35,000. Current savings: £5,000. Monthly contribution: £500 (£333 of which goes into LISA, £167 into other savings). Rate: 4% AER on LISA, 5% on other savings.

With LISA 25% bonus on annual £4,000 contribution = £1,000/year bonus. Result: 4 years. Without LISA, same contribution at average 4.5% AER would take 4 years 10 months — LISA saves 10 months.

Worked example 4 — couple saving £1,200/month

Target: £37,500 (15% on £250k). Current savings: £8,000. Joint monthly contribution: £1,200. Rate: 4.5% AER.

Result: 2 years 2 months. Higher monthly contribution disproportionately shortens timeline because there's less time for the target to drift (less inflation exposure on property prices over a shorter horizon).

Savings strategies

Lifetime ISA (LISA)

The most useful single product for first-time buyers:

• Save up to £4,000/year.
• Government adds 25% bonus (£1,000/year).
• Must be 18-39 to open (can contribute until 50).
• Property must be ≤£450,000 to qualify for first home purchase.
• 25% penalty on non-qualifying withdrawals (effectively losing the bonus + a bit).
• Stocks-and-shares LISA available — higher long-term return potential, more risk.

For a 25-year-old saving 5 years to a £45,000 deposit target: max LISA contribution = £20,000 + £5,000 bonus = £25,000 of the target. The bonus alone is worth roughly 6 months of additional contribution.

Fixed-term cash savings

For amounts beyond LISA limits, lock in higher rates with 1-3 year fixed-term accounts. Trade-off: cannot access funds without penalty during the term.

Premium Bonds

Returns vary but average around 4% in 2026. Useful for the part of your savings you want fully accessible without notice. Not a growth investment but doesn't lose value to inflation as fast as a 0% current account.

Stocks and shares ISA

Higher long-term return potential (~6-8% historical average) but volatile. Suitable only for deposit timelines beyond 5 years. Don't put your deposit in equities if you'll need it in 2 years.

Workplace bonuses and side income

Direct annual bonuses straight to deposit savings. Track side-hustle income separately and channel to LISA where possible.

Deposit savings myths

"I need to save the deposit in cash"

Not entirely — LISA contributions don't count as cash savings until withdrawn. They count as your deposit at completion. So "cash savings" can be lower than "deposit pot" if part is in LISA.

"I can use a credit card for the deposit"

Generally no — residential mortgage lenders need to see a sustainable deposit source. A small portion via 0% credit card is sometimes tolerated but reduces affordability and may flag at underwriting.

"Friends and family can loan me the deposit"

Usually no — most lenders distinguish between gifted deposit (acceptable with letter from donor) and loaned deposit (most lenders refuse). A gift means the donor has no future claim on the property or the funds.

"5% is good enough"

5% works for some, but the rate difference vs 10% (typically 30-50bps) means you'll pay £15-£25/month more on a £200k mortgage. Over 5 years that's £900-£1,500.

"I need 25% deposit to buy in the UK"

A misconception — 25% is the BTL minimum, not residential. Residential FTB mortgages start at 5%. 10% is the typical FTB target.

How to find the extra £100-£200/month

For households struggling to save £500/month, common cuttable categories:

• Subscriptions: Audit all (streaming, gym, software, magazines). Easy £50-£100/month savings.
• Eating out / takeaway: A £4 coffee + £15 lunch + £30 weekend takeaway sums to £400+/month.
• Mobile and broadband: Switch providers; save £15-£30/month.
• Insurance: Shop around annually; save £100-£200/year.
• Bank account: Switch to a paid current account with cashback or interest; net £10-£30/month.
• Energy supplier: Annual switch saves £100-£300.
• Pension contribution: Reducing during deposit-saving phase frees up cash; reconsider after purchase.

The trade-off between target and timeline

Three lever choices:

1. Lower target property price. A £200k target needs a £20k deposit (10%); a £250k target needs £25k. Each extra £50k of target adds £5k of deposit needed.
2. Lower deposit percentage. 5% on £250k is £12,500; 10% is £25k; 15% is £37,500. 5% saves you ~3 years of saving but adds ~£20/month to your mortgage payment for the life of the fix.
3. Increase monthly contribution. Doubling monthly contribution from £400 to £800 roughly halves the timeline.

What happens during a savings phase that you should plan for

Property prices change

UK house prices have grown 3-5% per year long-term. A 4-year saving phase might see your target property price rise 15-20%. Build a buffer into your headline target.

Interest rates change

Both savings rates and mortgage rates move. Higher savings rates accelerate your saving; higher mortgage rates increase the cost of buying.

Personal income changes

Pay rises and bonuses can dramatically accelerate the timeline. Make sure your savings contribution scales with your income — "save 20% of every pay rise" is a powerful rule.

Government scheme changes

LISA, Help to Buy ISA, First Homes, and Shared Ownership all have eligibility rules that change over time. Check current rules annually.

What to do when you hit your target

1. Open a separate "ready to buy" account.
2. Keep funds in cash (savings, ISA, premium bonds) — don't put your deposit at market risk close to purchase.
3. Update your AIP if it's expired.
4. Refresh your mortgage broker on income and circumstances.
5. Start property viewings.
6. Use the home buying cost calculator to plan total cash needed at completion.

Why compounding matters more on longer timelines

Compound interest works harder over longer periods. At 4.5% AER, the difference between simple and compound on a 2-year savings plan is small — about £100 on a £12,000 pot. On a 5-year plan, the difference is £1,200+. On a 7-year plan, over £2,200. Longer saving timelines should weight interest rate more heavily in product selection because the cumulative compound effect grows meaningfully. The calculator handles this automatically through its month-by-month compounding model. If you're comparing different savings products with similar headline rates but different compounding frequencies, the calculator's compounded figure reflects what you'll actually accumulate.

Couples and joint deposits

Two earners save dramatically faster than one. A couple each contributing £500/month + £4,000/year each to LISAs can save £30,000+ a year toward deposit. The same target (e.g. £50,000) takes 2 years for a couple vs 5 years for a single saver at half the rate. Coordinate your strategy:

• Both open LISAs if both qualify (under 40, no prior home ownership).
• Both contribute the £4,000/year max to maximise government bonus (£2,000 free between you).
• Hold remaining cash savings in joint or separate fixed-term accounts.
• Confirm both names will be on the deeds — required for both LISAs to be used.
• Watch the £450,000 LISA property cap — relevant in London and South East.

Tracking progress vs goal

Multi-year savings goals fail more from drift than from catastrophe. Set up monthly tracking:

• Year 1 check: Are you on the curve? If you're 10%+ behind plan, course-correct now.
• Annual review: Adjust contribution as income changes. Increase with pay rises.
• Quarterly automation check: Confirm direct debits to LISA and savings account are still hitting target amounts.
• Major life event triggers: Pay rise, new job, bonus, inheritance, redundancy — all trigger replan.

Use the calculator periodically with updated current-savings figure to confirm timeline. Many savers reach goal 6-12 months earlier than original plan thanks to compounding and gradual contribution increases.

What if your monthly contribution must vary?

The calculator assumes a constant monthly contribution, but real saving rates often vary by month — higher bonus months, lower holiday months, occasional extra contributions from gifts. To handle this, use an average monthly figure across the year. For a buyer who normally saves £400 but adds a £2,400 bonus once a year, the equivalent monthly rate is £600. Re-run the calculator annually with updated current-savings figure to keep the projection grounded in reality.

What to avoid during deposit saving

• Dipping into deposit savings. Once you start using the pot for non-essentials, it becomes a sinking ship.
• High-risk investments. Cryptocurrency, individual stocks, leveraged products — all wrong for a short-term goal.
• New consumer debt. Car finance, credit card splurges reduce affordability and prolong the timeline.
• Premature property viewings. Avoid attaching to specific properties until you have ~80%+ of the deposit.
• Lifestyle inflation. Resist letting expenses creep up with income — channel raises to savings.

Side-hustles for deposit acceleration

For many savers, the difference between 4 years and 3 years to deposit is £200-£400/month of additional savings. Sources:

• Overtime at primary job.
• Freelance work in your existing skill area.
• Renting a room (if owner-occupier of a current property).
• Online selling (eBay, Vinted, Facebook Marketplace).
• Gig economy: delivery driving, tutoring, pet care.
• Skills-based platforms: Fiverr, Upwork, PeoplePerHour.

Channel additional income directly to deposit. Many savers auto-transfer side income to LISA before it touches the main account — friction prevents reabsorption.

Frequently asked questions

How does the deposit savings goal calculator work?

You enter target property price, deposit percentage, current savings, and monthly contribution. The calculator computes target deposit, remaining amount, and months/years required.

How long does it take to save a UK house deposit?

£25,000 (10% on £250k) at £500/month with 4.5% AER takes about 4 years. £37,500 (15% on £250k) takes about 5.5 years.

Should I use a Lifetime ISA?

Yes — for most first-time buyers under 40 buying under £450,000. Save up to £4,000/year; government adds £1,000 bonus.

What interest rate should I assume?

In 2026, easy-access savings pay 4-5% AER. Fixed-term 5-5.5%. LISA platforms 3.5-4.5% on top of the bonus. The calculator defaults to 4.5%.

What if I can't save the full amount?

Lower target price; use 5% mortgage; combine with shared ownership; family-assisted mortgage; extend timeline; increase income.

Does the calculator account for inflation?

No — figures are nominal. UK house prices have grown 4-5% per year long-term. Plan a 10-15% buffer above the headline figure for multi-year timelines.

Should I prioritise deposit savings or paying off debt?

Pay off debt with interest rate above your savings rate — credit card at 20%+ APR almost always wins vs savings at 5%.

What's a realistic monthly savings target?

15-25% of net income is a strong rate. £500-£800/month common for typical FTBs in 2026. £1,000+/month requires high income or substantial restraint.

Pre-existing savings — how to model them

Many first-time buyers approach their deposit target with meaningful pre-existing cash. Enter this as "current savings" and the calculator subtracts it from the target before computing months needed. Worked example: target £30,000, current £8,000, monthly contribution £600 at 4.5% AER — gives 2 years 8 months. Without any current savings, the same monthly contribution would take 4 years to reach £30,000. Starting from £5,000+ in pre-existing savings materially shortens the runway.

Tax-efficient deposit savings stack in 2026

For the most tax-efficient saving toward a £30,000-£60,000 deposit target in 2026:

1. Lifetime ISA first — £4,000/year + £1,000 bonus. Annual £5,000 from the start.
2. Cash ISA second — £16,000/year remaining of £20,000 ISA allowance. Tax-free interest.
3. Premium Bonds third — for any cash above ISA limits. Prizes tax-free.
4. Fixed-term savings fourth — for any remainder. Best rates lock 1-3 years.

The hierarchy maximises both government bonus and tax efficiency. A couple maxing both LISAs gets £2,000/year of free government money — accelerating a 5-year saving plan into 4 years for the same monthly contribution.

Savings rate trends to watch

Cash savings rates move with Bank Rate. In 2026, easy-access rates run 4-5% AER but won't stay there indefinitely. If you're saving over 3+ years:

• Lock part of your savings in 2-3 year fixed-term accounts when rates are high.
• Keep emergency reserve in easy-access (immediate withdrawal).
• Re-evaluate annually — high-interest accounts often time-limited then drop.

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Last reviewed: 6 June 2026.