ROI is one of the most common ways to measure whether an investment, project or purchase has been worthwhile.
It stands for return on investment and shows how much profit or benefit you made compared with how much you put in.
ROI is often used for investments, property, business spending, marketing campaigns, training, equipment, side hustles and personal finance decisions.
But there is one important point to understand:
A good ROI depends on the context.
A 5% ROI might be good for one situation and poor for another. To measure ROI properly, you need to look at the percentage return, the time period, the level of risk, the costs involved and what else you could have done with the money.
This guide explains what ROI means, how to calculate it, what counts as a good ROI, and the common mistakes to avoid.
What Does ROI Mean?
ROI means return on investment.
It measures the gain or loss from an investment compared with the amount invested.
For example, if you spend £1,000 and make £1,200 back, your gain is £200.
Your ROI shows that £200 gain as a percentage of the £1,000 you invested.
In this case, the ROI is 20%.
ROI is useful because it allows you to compare different opportunities using a simple percentage.
ROI Formula
The basic ROI formula is:
ROI = Net profit ÷ Investment cost × 100
Where:
- Net profit is the amount you made after subtracting your original investment
- Investment cost is the amount you put in
- ROI is shown as a percentage
You can also write it as:
ROI = (Final value – Initial cost) ÷ Initial cost × 100
For example:
- Initial investment: £5,000
- Final value: £6,000
- Net profit: £1,000
Calculation:
£1,000 ÷ £5,000 × 100 = 20%
So, the ROI is 20%.
How to Calculate ROI Step by Step
To calculate ROI:
- Start with the amount you invested.
- Work out the final value or return.
- Subtract the original investment from the final value.
- Divide the profit by the original investment.
- Multiply by 100.
Example:
- You invest £2,000
- You receive £2,500 back
- Your profit is £500
ROI calculation:
£500 ÷ £2,000 × 100 = 25%
Your ROI is 25%.
That means you made a return equal to 25% of your original investment.
Simple ROI Examples
| Investment Cost | Final Value | Profit | ROI |
| £500 | £600 | £100 | 20% |
| £1,000 | £1,100 | £100 | 10% |
| £2,000 | £2,500 | £500 | 25% |
| £5,000 | £6,000 | £1,000 | 20% |
| £10,000 | £11,500 | £1,500 | 15% |
These examples show why the percentage matters.
A £100 profit may be excellent on a £500 investment, but less impressive on a £5,000 investment.
What Is a Good ROI?
A good ROI is a return strong enough to justify the cost, risk, and time involved.
No single number counts as a good ROI in every situation.
For example:
- A 3% to 5% ROI may be reasonable for a low-risk savings-style return.
- A 7% to 10% ROI may be considered attractive for some longer-term investment scenarios.
- A 20%+ ROI may look strong, but may involve more risk, more work or a shorter-term campaign.
- A negative ROI means the investment lost money.
The important thing is not just the ROI percentage. You also need to ask what it took to achieve that return.
A 15% ROI with low risk and little effort could be excellent.
A 15% ROI with high risk, high stress and lots of hidden costs may be less attractive.
Why Time Matters When Measuring ROI
One of the biggest problems with basic ROI is that it does not show how long the return took.
For example:
- Investment A makes 20% in one year
- Investment B makes 20% in five years
Both have a 20% ROI, but they are not equally attractive.
The first investment grew much faster.
This is why annualised ROI can be more useful when comparing investments over different time periods.
What Is Annualised ROI?
Annualised ROI shows the average yearly return over a period.
It helps you compare investments that lasted for different lengths of time.
For example, a 30% ROI over 3 years is not the same as a 30% ROI in 1 year.
A simple approximate annual ROI would be:
30% ÷ 3 years = 10% per year
However, this simple method does not account for compounding. For a more accurate annualised return, you would use a compound annual growth rate calculation, often called CAGR.
ROI vs CAGR: What Is the Difference?
ROI measures the total return over the full investment period.
CAGR estimates the average annual growth rate, assuming the investment grew at a steady compounded rate.
For example:
- You invest £10,000
- It grows to £15,000
- The total ROI is 50%
But if that took:
- 2 years, the annual growth rate is strong
- 10 years, the annual growth rate is much lower
That is why CAGR is often better for comparing long-term investments, while ROI is useful for quick, simple comparisons.
ROI Example: Investment Return
Let’s say you invest £8,000 and later sell the investment for £9,600.
Your profit is:
£9,600 – £8,000 = £1,600
Now calculate ROI:
£1,600 ÷ £8,000 × 100 = 20%
Your ROI is 20%.
This tells you the investment returned 20% overall. But to judge whether that is good, you need to know whether it happened over 6 months, 2 years or 10 years.
ROI Example: Property Renovation
ROI is often used when assessing home improvements or property projects.
For example:
- Renovation cost: £15,000
- Increase in property value: £25,000
- Estimated gain: £10,000
ROI calculation:
£10,000 ÷ £15,000 × 100 = 66.7%
On paper, that looks like a very strong ROI.
But property ROI can be tricky because you also need to consider:
- Estate agent fees
- Stamp duty, where relevant
- Legal costs
- Mortgage costs
- Time taken
- Labour
- Tax implications
- Whether the value increase is only an estimate
A renovation may add value, but the true ROI depends on the real sale price and all associated costs.
ROI Example: Marketing Campaign
Businesses often use ROI to measure marketing performance.
For example:
- Campaign cost: £2,000
- Revenue generated: £8,000
- Gross return: £6,000
Simple ROI:
£6,000 ÷ £2,000 × 100 = 300%
That looks excellent. But this only tells part of the story.
To measure marketing ROI properly, you may also need to subtract:
- Product costs
- Delivery costs
- Staff time
- Agency fees
- Software costs
- Discounts or vouchers
- Refunds
- VAT treatment, if relevant
- Repeat purchase value
For a more accurate view, marketing ROI should usually be based on profit, not just revenue.
ROI Example: Training or Education
ROI can also apply to training, qualifications or professional development.
For example:
- Course cost: £1,200
- Salary increase after qualification: £3,000 per year
The first-year ROI could be:
£3,000 – £1,200 = £1,800 net gain
£1,800 ÷ £1,200 × 100 = 150% ROI
This looks strong, but there may be other factors to consider:
- Time spent studying
- Exam fees
- Travel costs
- Whether the salary increase is guaranteed
- Longer-term career benefits
- Non-financial benefits, such as confidence or job security
Not every return is purely financial.
ROI Example: Business Equipment
A business might buy equipment to save time or increase output.
For example:
- Equipment cost: £4,000
- Extra annual profit generated: £1,500
First-year ROI:
£1,500 ÷ £4,000 × 100 = 37.5%
If the equipment continues to generate extra profit for several years, the total ROI could be much higher.
However, a proper calculation should also consider:
- Maintenance
- Repairs
- Insurance
- Training
- Depreciation
- Finance costs
- Resale value
Positive ROI vs Negative ROI
ROI can be positive, zero or negative.
Positive ROI
A positive ROI means the investment made more than it cost.
Example:
- Invested: £1,000
- Final value: £1,200
- ROI: 20%
Zero ROI
A zero ROI means you got back exactly what you put in.
Example:
- Invested: £1,000
- Final value: £1,000
- ROI: 0%
Negative ROI
A negative ROI means the investment lost money.
Example:
- Invested: £1,000
- Final value: £800
- Loss: £200
- ROI: -20%
Negative ROI isn’t always a failure if there were other benefits, such as learning, brand awareness, or long-term positioning. But financially, it means the return was lower than the cost.
What Makes an ROI Good or Bad?
A good ROI depends on several factors.
1. Risk
Higher-risk investments usually need a higher expected return to be worthwhile.
A low-risk 4% return may be acceptable. A high-risk 4% return may not be.
2. Time
A 20% ROI over one year is very different from 20% over ten years.
Always consider the time period.
3. Effort
Some returns require a lot of active work.
For example, a side hustle may produce a high ROI on cash invested but require hundreds of hours of unpaid time.
4. Liquidity
Liquidity means how easily you can access your money.
Cash savings are usually liquid. Property and business assets are less liquid.
Less flexible investments may need a higher return to feel worthwhile.
5. Hidden Costs
ROI can look better than it really is if you forget costs.
Always include all relevant expenses.
6. Opportunity Cost
Opportunity cost means what else you could have done with the money.
For example, if one option gives a 5% return and another similar-risk option gives 8%, the 5% option may not be the best use of funds.
Why ROI Can Be Misleading
ROI is useful, but it can oversimplify things.
The biggest weakness is that ROI does not automatically include time, risk or cash flow.
For example, a 50% ROI sounds good, but it matters whether that return took:
- 3 months
- 3 years
- 30 years
ROI can also be misleading if the calculation leaves out important costs.
A business might say a campaign generated a 400% ROI, but if that is based on revenue rather than profit, the true return may be much lower.
ROI Based on Revenue vs Profit
For proper ROI, it is usually better to use profit rather than revenue.
Revenue-Based ROI
Revenue-based ROI looks at sales generated.
Example:
- Campaign cost: £1,000
- Sales revenue: £4,000
- Revenue return: £3,000
- ROI: 300%
This looks strong, but it ignores the cost of delivering the product or service.
Profit-Based ROI
Profit-based ROI uses the actual profit after costs.
Example:
- Campaign cost: £1,000
- Sales revenue: £4,000
- Product and delivery costs: £2,200
- Profit after costs: £800
Profit-based ROI:
£800 ÷ £1,000 × 100 = 80%
That is still positive, but much lower than 300%.
This is why profit-based ROI gives a more realistic view.
How to Measure ROI Properly
To measure ROI properly, follow these steps.
1. Define the Investment
Be clear about what you are measuring.
Are you calculating ROI on:
- A financial investment?
- A property project?
- A marketing campaign?
- A course?
- A business purchase?
- A new employee?
- A piece of software?
2. Include All Costs
Include the full cost of the investment, not just the obvious purchase price.
This may include:
- Fees
- Delivery
- Labour
- Tax
- Maintenance
- Software
- Insurance
- Finance costs
- Professional services
- Your own time, if relevant
3. Use Net Profit Where Possible
ROI should usually be based on net gain, not headline revenue.
4. Set a Clear Time Period
State whether the ROI is over one month, one year, five years or the full lifetime of the investment.
5. Compare Like for Like
Do not compare a one-month ROI with a five-year ROI without adjusting for time.
6. Consider Risk
A higher return is not automatically better if the risk is much higher.
7. Review Non-Financial Benefits
Some investments produce benefits that are harder to measure, such as:
- Better customer experience
- Time saved
- Reduced stress
- Improved brand awareness
- Higher staff retention
- Better quality
- Lower risk
These may not appear neatly in the ROI figure, but they can still matter.
ROI and Payback Period
ROI tells you the percentage return.
Payback period tells you how long it takes to recover the original investment.
For example:
- Investment cost: £5,000
- Annual profit generated: £1,250
Payback period:
£5,000 ÷ £1,250 = 4 years
So, it would take 4 years to recover the original investment.
A project can have a good ROI but a long payback period. Whether that is acceptable depends on your goals and cash flow.
ROI and Break-Even Point
The break-even point is where you have recovered your costs but have not yet made a profit.
For example, if a campaign costs £1,000, you need to generate enough profit to cover that £1,000 before the ROI becomes positive.
Break-even matters because it shows the minimum return needed before an investment starts paying off.
For a business, knowing the break-even point can help decide whether an investment is realistic.
ROI for Personal Finance Decisions
ROI is not just for investors or businesses. It can also help with everyday financial decisions.
You might use ROI to compare:
- Paying for a qualification
- Upgrading home insulation
- Buying energy-efficient appliances
- Starting a side hustle
- Renovating a property
- Paying for professional advice
- Buying tools or equipment
However, personal ROI is not always purely financial.
For example, home insulation may save money on bills, but it may also make your home warmer and more comfortable. That benefit matters, even if the ROI calculation doesn’t fully capture it.
ROI for Business Decisions
Businesses use ROI to decide whether spending money is likely to be worthwhile.
Common examples include:
- Advertising campaigns
- New software
- Hiring staff
- Machinery
- Training
- Website redesigns
- SEO
- Stock purchases
- Automation tools
For business ROI, it is especially important to use profit rather than revenue.
A campaign that brings in sales may still be unprofitable if margins are low or fulfilment costs are high.
ROI for Marketing and SEO
ROI is often used in marketing, but it can be difficult to measure perfectly.
For example, SEO may generate leads and sales over a long period, rather than immediately. A blog post, calculator or landing page may keep bringing in traffic months or years after it is published.
This can make SEO ROI harder to calculate than paid ads, where spend and conversions are often easier to track.
For marketing ROI, consider:
- Campaign cost
- Leads generated
- Conversion rate
- Average order value
- Profit margin
- Customer lifetime value
- Time lag before results
- Repeat purchases
- Brand awareness
A campaign may not look profitable immediately but may still create long-term value.
What Is a Good ROI for Marketing?
A good marketing ROI depends on the business model, margins and growth goals.
For some businesses, a 2:1 return may be acceptable. That means £2 generated for every £1 spent.
For others, especially with low margins, a higher return may be needed.
For example:
- High-margin service business: lower revenue ROI may still be profitable
- Low-margin ecommerce business: needs stronger revenue return to cover costs
- Subscription business: initial ROI may look weak, but customer lifetime value may improve the picture
- Local business: leads may be more valuable than immediate online sales
The best way to judge marketing ROI is to connect it to profit and customer value, not just clicks or impressions.
What Is a Good ROI for Property?
A good ROI for property depends on whether you are looking at rental yield, capital growth, renovation profit or total return.
For example, a landlord may care about rental yield, while a homeowner may care about whether a renovation increases property value.
Property ROI can be affected by:
- Purchase price
- Deposit
- Mortgage interest
- Renovation costs
- Maintenance
- Insurance
- Letting agent fees
- Void periods
- Tax
- Legal fees
- Sale price
- Local market conditions
A simple ROI calculation can be useful, but property decisions usually need a fuller view of cash flow and risk.
What Is a Good ROI for Savings?
For cash savings, ROI is usually linked to the interest rate.
A “good” return on savings depends on available rates, whether the account is easy access or fixed-term, and how inflation compares.
Cash savings are generally lower risk than investing, so expected returns are usually lower.
When comparing savings ROI, check:
- Interest rate
- AER
- Access restrictions
- Tax on savings interest
- Whether the rate is fixed or variable
- Whether inflation is reducing real value
A lower ROI may still be suitable if you need easy access and low risk.
What Is a Good ROI for Investments?
For investments, a good ROI depends on the asset, time period and risk level.
Higher potential returns usually come with higher volatility or the possibility of loss.
A good investment ROI should be judged against:
- Your goals
- Your risk tolerance
- Your time horizon
- Inflation
- Fees
- Tax
- Comparable investments
- Whether the return is annualised
A total ROI figure is useful, but it should not be the only measure.
ROI Checklist
Before deciding whether an ROI is good, ask:
- What is the total return?
- How long did it take?
- What were the full costs?
- Is the return based on revenue or profit?
- What risks were involved?
- Could the money have done better elsewhere?
- How much effort was required?
- Is the return repeatable?
- Is the money easy to access?
- Are there non-financial benefits?
This helps you avoid judging an investment by the headline percentage alone.
Final Thoughts on ROI
ROI is a simple but useful way to measure whether an investment has produced a worthwhile return.
The basic formula is easy:
ROI = Net profit ÷ Investment cost × 100
But a proper ROI calculation should go beyond the headline percentage.
A good ROI depends on the time period, risk, costs, effort, cash flow and alternative options. A high ROI is not always better if it comes with high risk or hidden costs. A lower ROI may still be good if it is reliable, low-risk and supports your wider goals.
The best approach is to use ROI as a starting point, not the full answer.
A return on investment calculator can help you quickly compare different scenarios, but the final decision should also consider the bigger picture.
ROI FAQ
What does ROI mean?
ROI stands for return on investment. It shows how much profit or benefit you made compared with how much you invested.
How do you calculate ROI?
Use this formula:
ROI = Net profit ÷ Investment cost × 100
For example, if you invest £1,000 and make £200 profit, your ROI is:
£200 ÷ £1,000 × 100 = 20%
What is a good ROI?
A good ROI depends on the investment, time period, risk and costs. A 5% ROI may be good for a low-risk option, while a higher-risk project may need a much higher return to be worthwhile.
Is a higher ROI always better?
Not always. A higher ROI may involve more risk, more effort, less flexibility or hidden costs. You should compare ROI alongside time, risk and cash flow.
What is a bad ROI?
A bad ROI usually doesn’t justify the cost, risk, or effort. A negative ROI means the investment lost money financially.
What is a 100% ROI?
A 100% ROI means you doubled your original investment. For example, if you invest £1,000 and make £1,000 profit, your ROI is 100%.
What is the difference between ROI and profit?
Profit is the cash amount you made. ROI shows that profit as a percentage of the original investment.
For example, £500 profit on a £1,000 investment is a 50% ROI.
Should ROI be based on revenue or profit?
ROI should usually be based on profit, not revenue. Revenue-based ROI can look misleading because it may ignore costs such as labour, delivery, fees, stock and tax.
Why is time important in ROI?
Time matters because the same ROI can mean different things over different periods. A 20% ROI in one year is much stronger than a 20% ROI over ten years.
What is annualised ROI?
Annualised ROI estimates the average yearly return from an investment. It is useful when comparing investments that lasted for different lengths of time.