Zinsora — Free Financial Calculators

Finance made
simple.

Interest, loans, returns – all the essential calculations, directly in your browser, no sign-up needed.

Whether you're planning a loan, looking to invest your savings, or simply want to understand how interest really works – Zinsora gives you precise calculators with clear answers. Directly in your browser, no sign-up needed, free.

Our calculators are designed to make complex financial topics easy to understand. The Interest Calculator shows you the difference between simple and compound interest. The Loan Calculator explains loan types and creates a full amortisation schedule. The Return Calculator helps you compare savings plans, lump-sum investments and property – including inflation. The Budget Calculator shows how much of your salary is left at month-end.

All calculations run directly in your browser. Your data never leaves your device.

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Interest Calculator
Compound interest, savings rates & term
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Loan Calculator
Annuity, repayment & schedule
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Return Calculator
ETF savings, lump sum & property
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Budget Calculator
Monthly budget & savings potential

Interest Calculator – Compound Interest & Savings

Calculate interest for savings accounts, fixed deposits and savings plans — with compound interest

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Years

What does the Interest Calculator calculate?

Simple Interest Interest is only calculated on the original capital – without compounding of returns.
Compound Interest Interest is calculated on the capital and on previously earned interest. Over time this creates exponential growth.
Annual Deposit Regular annual contributions in addition to the starting capital – for savings plans or easy-access accounts.

The compound interest effect is one of the most powerful mechanisms in saving and investing. The longer the investment period, the stronger it works. Even small differences in interest rate lead to enormous differences in final capital over 20–30 years.

Tip: Compare simple interest and compound interest with the same amount – and see how large the difference is after 20 years.

Ratgeber

Everything you need to know
about our calculators

Interest Calculator, Loan Calculator, Return Calculator und Budget Calculator – wofür werden sie genutzt und was bringen sie dir?

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Ratgeber · Sparen
The Interest Calculator

What is it used for?

The Interest Calculator helps you calculate the growth of your capital over time – whether for a savings account, fixed deposit or savings plan. You can choose between simple and compound interest and instantly see how much your money grows through the compound interest effect.

Typical use cases

  • Plan a savings account or fixed deposit
  • Understand and visualise the compound interest effect
  • Compare different interest rates
  • Combine savings rates with starting capital

Your advantages

  • Instant calculation without sign-up
  • Shows the real difference between simple and compound interest
  • Sliders for quickly testing different scenarios
  • All data stays in your browser
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Ratgeber · Kredit
The Loan Calculator

What is it used for?

The Loan Calculator helps you plan a mortgage or loan. It calculates your monthly payment, total costs and creates a full amortisation schedule – for annuity loans, repayment loans and bullet loans.

Typical use cases

  • Plan property financing or purchase
  • Realistically assess monthly payment
  • Compare different loan types
  • View amortisation schedule year by year

Your advantages

  • Three loan types in one calculator
  • Full amortisation schedule at a glance
  • Visual cost breakdown (repayment vs. interest)
  • No bank, no sales pressure – just numbers
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Ratgeber · Investieren
The Return Calculator

What is it used for?

The Return Calculator shows how your invested capital can develop long-term – whether as a monthly ETF savings plan, a lump-sum investment or a property investment. Including inflation adjustment, you see the real value of your wealth.

Typical use cases

  • Simulate ETF savings plan over years
  • Plan a lump-sum investment in stocks or funds
  • Realistically calculate property returns
  • Factor inflation into purchasing power

Your advantages

  • Three investment types directly comparable
  • Inflation adjustment for realistic planning
  • Shows capital gains vs. contributions clearly
  • Ideal for long-term wealth planning
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Ratgeber · Finanzen
The Budget Calculator

What is it used for?

The Budget Calculator helps you keep track of your monthly household budget. Enter income (salary, Part-time Job, Child Benefit) ande Fixed Costs und variable expenses ein – und sieh sofort, wie viel am Monatsende übrig bleibt.

Typical use cases

  • Plan monthly budget in a structured way
  • Einsparungspotenziale bei Abos & Fixed Costs erkennen
  • Build emergency fund and reserves purposefully
  • Distribute surplus wisely between saving & investing

Your advantages

  • Dynamic rows – add your own categories
  • 50-30-20 rule as instant comparison
  • Concrete recommendations: emergency fund, debt, ETF
  • All data stays exclusively in your browser
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Guide · Loans
Mortgage Overpayment

When does it make sense?

Overpay the mortgage or invest? The decision comes down to comparing your mortgage rate against achievable after-tax returns. Above 4–5%, overpayment is hard to beat.

What you'll learn

  • Overpayment vs. ISA/ETF: direct comparison
  • How tax changes the maths
  • Hybrid strategy: repay AND invest
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Guide · Saving
Easy Access vs Fixed-Rate

Which pays more in 2026?

Easy access savings are flexible, fixed-rate bonds pay more. When each makes sense – and how a savings ladder gets the best of both worlds.

What you'll learn

  • Current rates 2026 compared
  • FSCS protection and limits
  • Fixed-rate ladder strategy
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Guide · Finance
50-30-20 Rule

Budgeting made simple

50% for needs, 30% for wants, 20% for saving. The simplest way to split your salary – no spreadsheet required. Works even in expensive cities.

What you'll learn

  • 50-30-20 with concrete examples
  • What to do when rent is too high
  • Most common budgeting mistakes
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Guide · Investing
Inflation & Purchasing Power

What is your money really worth?

At 3% inflation, £100,000 is worth only £55,000 after 20 years. What actually protects against inflation – and why easy access savings aren't enough.

What you'll learn

  • Calculate purchasing power loss
  • Best inflation hedges compared
  • Real return vs. nominal return
FAQ

Frequently Asked Questions

Answers to the most important questions about interest, loans, returns and budgeting

With simple interest, returns are always calculated only on the original capital. With compound interest, the interest earned is added to the capital and in the next year is also subject to interest. Over long periods this leads to exponential growth – the so-called compound interest effect. Use our Interest Calculator to see the difference.
This depends on the current interest rate, the term and the loan type. For an annuity loan of £300,000 at 3.5% and 2% initial repayment, the monthly payment is approx. £1,375. Over 25 years you pay around £112,000 in interest. Enter your exact figures into our Loan Calculator to get your personal result.
Broadly diversified ETFs on the MSCI World or S&P 500 have historically averaged 6–8% per year – after inflation. This is not a guarantee for the future. With our Return Calculator you can run different scenarios and see how £100/month could develop over 20 or 30 years.
With an annuity loan you always pay the same monthly payment (annuity) throughout the entire term. This payment consists of an interest component and a repayment component. Over time the interest component falls (because the outstanding balance decreases) and the repayment component rises. It is the most common form of property financing.
No. All calculations on Zinsora run entirely in your browser. Your inputs are never transmitted to a server, saved, or shared with third parties. You can use all calculators completely anonymously and without signing up.
The gross yield of a property is calculated as: (Annual rental income ÷ Purchase price) × 100. For a purchase price of £300,000 and £12,000 annual rental income that gives a gross yield of 4%. Our Return Calculator calculates this automatically and also shows appreciation over the years. Note: gross yield does not account for purchase costs, maintenance or taxes.
Experts recommend saving at least 20% of your net income. For an income of £2,500/month that would be £500/month. The most important thing: first build an emergency fund of 3–6 months' salary, then invest the surplus – ideally in a broadly diversified ETF savings plan. Use our Budget Calculator to find your personal savings rate.
An emergency fund is a financial reserve exclusively for unforeseen expenses such as car repairs, illness or job loss. Experts recommend 3–6 months of net salary as a buffer – for an income of £2,500/month that is £7,500–£15,000. Keep it in an easy-access savings account (not invested in stocks) so it is available immediately when needed.
About Zinsora

Why Zinsora?

Zinsora was founded because financial topics are too often presented in unnecessarily complicated ways. Our goal is to provide you with precise, understandable calculators – without registration, without hidden costs, without your data leaving your device. All calculations run entirely in your browser. Whether you are planning a property loan, optimising your ETF savings plan, structuring your monthly budget or identifying savings potential – Zinsora gives you the numbers you need.

⚠️ All calculations are non-binding and serve as guidance only. They do not replace professional financial, tax or legal advice.