Investment Calculator
Project UK investment growth, stocks and shares ISA value, annual return, fees, dividends, inflation impact, and profit scenarios.
How It Works
UK users want a practical ISA and investment projection that shows contributions, growth, fees, inflation, and the difference between cash interest and market returns. Enter your values, review the instant result, save Scenario A, compare Scenario B, then use Share or Print if you need a record.
Investment Calculator Guide
Use this Investment Calculator for a fast UK-focused calculation with clear inputs, instant results, scenario comparison, last 5 calculations, shareable links, and print-friendly output. It is built around the search intent behind: isa calculator, stocks and shares isa calculator, isa calculator uk, profit calculator, junior isa calculator, interest calculator simple interest, isa calc.
Last Updated: June 2026
What is Investment Calculator?
UK users want a practical ISA and investment projection that shows contributions, growth, fees, inflation, and the difference between cash interest and market returns. The page combines a practical calculator with an explanation, examples, tables, and internal links so users can move from one quick answer to a better understanding of the method.
UK context matters. GOV.UK lists the 2026 to 2027 adult ISA allowance as £20,000, and the Junior ISA limit as £9,000. Bank of England Bank Rate was 3.75% in early June 2026, while ONS reported CPI inflation of 2.8% for April 2026. These figures are useful reference points, but account rates, fees, tax treatment, and investment performance can change.
How to use the Investment Calculator
- Enter the main value, expression, equation, balance, return, rate, or fraction.
- Choose the mode that matches your task, such as equation solving, compound growth, degree/radian mode, or fraction operation.
- Review the highlighted result and the plain-English working below it.
- Click Save Result to lock Scenario A, then change inputs to compare Scenario B.
- Use Share Link or Print when you want to keep the result for revision, records, or discussion.
Formula and method
Investment value compounds the starting balance and regular contributions by expected return minus platform fees. Nominal gain is future value minus contributions; real value adjusts the result for inflation.
| Input | Why it matters | What to check |
|---|---|---|
| Main amount or expression | Sets the problem the calculator solves. | Use the same order and symbols as your question. |
| Rate, return, operator, or mode | Changes the calculation method. | Check percent signs, brackets, degree/radian mode, and compounding. |
| Time period or second value | Affects growth, comparison, or the second side of a maths operation. | Use years, months, numerators, denominators, or equation sides consistently. |
| Result explanation | Shows the reasoning behind the answer. | Compare the step text with the original problem. |
Worked example
Example: £20,000 invested in a stocks and shares ISA with £300 monthly contributions, 6% expected return, 0.35% fees, and 3% inflation shows both nominal portfolio value and today-money value.
Common searches this tool answers
This page is written to answer real user variations such as isa calculator, stocks and shares isa calculator, isa calculator uk, profit calculator, junior isa calculator, interest calculator simple interest, isa calc. Some searches are precise calculations, such as 20 of 4000, 5 of 200000, 8 x 7, 10 divided by 3, or 0.5 in fraction form. Others are broader tasks, such as finding a maths solver, an ISA calculator, a compound interest calculator UK, or a scientific calculator online.
- Use exact numbers when the query is a direct calculation.
- Use the explanation when the query asks how to solve or how to multiply, divide, simplify, or estimate.
- Use UK assumptions for ISA, savings, inflation, and investment content.
- Switch calculation modes where the same search intent needs a different method, such as compound growth, monthly interest, percent of an amount, degree mode, radian mode, or fraction conversion.
For money that should stay low risk or easy to access, the Savings Calculator gives a clearer cash-interest comparison before you model stocks and shares ISA growth.
Accuracy, limits, and helpful use
This calculator is designed for helpful, people-first use: visible assumptions, clear working, useful examples, and no hidden signup. It does not replace a teacher, exam-approved calculator, bank quote, regulated financial adviser, tax professional, or official provider rate. Treat results as educational estimates and verify important numbers with the relevant school, provider, bank, HMRC, GOV.UK, ONS, Bank of England, or qualified professional source.
Editorial review
Formula Explanation
Investment value compounds the starting balance and regular contributions by expected return minus platform fees. Nominal gain is future value minus contributions; real value adjusts the result for inflation.
Trust and disclaimer
This calculator provides estimates for informational planning only. It is not tax, legal, payroll, accounting, investment, or professional advice. For exact figures, compare the result with your official documents, employer payroll portal, tax agency guidance, lender quote, or a qualified professional.
Last updated: June 2026. Reviewed by Editorial Team.
FAQ
Can this work as a stocks and shares ISA calculator?
Yes. Use ISA mode and enter the amount invested, monthly contribution, expected return, platform fee, and inflation assumption.
What ISA allowance does it use?
The content references the 2026 to 2027 adult ISA allowance of 20000 pounds from GOV.UK. The calculator lets you enter your own contribution amounts.
Can it calculate investment profit?
Yes. It estimates future value, total contributions, nominal profit, platform fees, and inflation-adjusted value.
Does it include Junior ISA planning?
It can estimate growth for a Junior ISA style contribution plan. GOV.UK lists the Junior ISA limit as 9000 pounds for 2026 to 2027.
What return should I enter?
Use a conservative expected annual return. Investments can fall as well as rise, and past performance does not guarantee future returns.
Does it calculate simple interest?
The calculator is designed for compound investment growth, but you can compare simple interest by setting contributions and returns conservatively.
Does it include tax?
ISA mode assumes tax-free wrapper growth. For general investment accounts, tax depends on dividends, capital gains, allowances, and personal circumstances.
Is this regulated investment advice?
No. It is a projection tool for education and planning. Consider a qualified adviser for investment decisions.
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