VAN vs TIR: Sometimes these two indicators give conflicting signals. Which should investors listen to?

When making investment decisions, VAN (Net Present Value) and TIR (Internal Rate of Return) are always closely linked. But here’s a painful truth: sometimes they give completely opposite conclusions. A project’s VAN might look very attractive, but its TIR is unimpressive; the reverse can also happen. What causes this contradiction? Today, let’s break down and clarify these two tools.

Starting with VAN: How much real profit can your investment generate?

Net Present Value (VAN) essentially asks: if you convert future cash flows into today’s money, can you make a profit?

Imagine you invest 1 million dollars into a project. The project will generate cash flows over the next 5 years. But these “future money” are not equal to “today’s money”—this involves a key concept called discount rate (tasa de descuento).

How to understand the discount rate? Simply put, it reflects the return you could earn elsewhere. If depositing money in a bank yields 5% annually, then your discount rate should be at least 5%.

The logic for calculating VAN is straightforward:

• Discount each year’s cash flow to “today’s value”
• Sum all discounted cash flows
• Subtract the initial investment

VAN > 0 = profit, VAN < 0 = loss. That’s it—simple and blunt.

VAN Practical Example 1: Profitable Project

Invest $10,000 in a project, which generates $4,000 annually for 5 years. Using a 10% discount rate:

Subtract initial investment of $10,000, VAN = $5162.49. Green light, invest.

VAN Practical Example 2: Loss-making Project

Opposite example: invest $5,000 in a financial product, get back $6,000 after 3 years, with an 8% annual interest rate.

3-year future value discounted to today: 6000 ÷ (1.08)³ = 4774.84 dollars

VAN = 4774.84 - 5000 = -225.16 dollars. This deal loses money.

The fatal weakness of VAN (must know)

VAN looks scientific, but in reality it often “fails”:

1. The discount rate is set artificially — you say 10%, I say 8%. Different rates can completely change the result.
2. Assumes future cash flows can be predicted precisely — a small estimation error can flip the VAN outcome.
3. Ignores “flexibility” — during project execution, you might want to adjust plans, but VAN assumes all decisions are fixed from the start.
4. Project scale comparison is tricky — investing 1 million to earn 500k looks better than 100k to earn 80k, but the efficiency might be higher in the smaller project.

TIR emerges: speaking in percentages

TIR (Tasa Interna de Retorno) shifts perspective: not asking how much you can earn, but what is your investment return rate.

Using the same example (invest 10,000, 5 years, $4,000/year): TIR answers “what is your annual return rate?” The answer is approximately 21.65%.

How to understand TIR? It’s the discount rate that makes the VAN equal to zero. If you use this TIR to discount cash flows, the net present value is exactly zero.

TIR > your benchmark rate (e.g., bank deposit rate) = worth investing
TIR < benchmark rate = not worth investing

A big advantage of TIR is expressing it as a percentage, making it easier to compare projects of different scales—more comfortable than VAN.

TIR is not perfect either

In practice, TIR has common issues:

1. Multiple answers — if cash flows change signs multiple times (non-conventional flows), there can be multiple TIRs, confusing to interpret.
2. Assumes reinvestment at TIR — in reality, you may not be able to reinvest at that rate, leading to overestimation of returns.
3. Poor at handling irregular cash flows — sudden losses followed by gains can distort TIR calculations.
4. Ignores inflation — a nominal TIR of 20% with 10% inflation effectively yields only 10% real return.

When VAN and TIR disagree, who should you trust?

The most tricky situation: VAN says YES, TIR says NO (or vice versa). When does this happen?

Usually:

• When cash flows are unevenly distributed (large upfront investments, irregular later cash flows)
• When the discount rate is set too high or too low
• When comparing projects of vastly different sizes

Recommended approach:

1. First look at VAN, because it directly answers “how much real profit?”
2. Then consider TIR as an “efficiency indicator”
3. Don’t blindly trust either; use other metrics (ROI, payback period, risk assessment)
4. Re-examine your assumptions: is your discount rate appropriate? Are your cash flow forecasts reliable?

Practical project selection tips

How to set a reliable discount rate?

Since the core of VAN and TIR calculations is the discount rate, choosing the wrong one invalidates all conclusions.

Some reference methods:

1. Opportunity cost approach — ask yourself: what return could I earn on similar risk projects elsewhere? That’s your baseline.
2. Risk-free rate method — start from government bond yields, add a risk premium.
3. Industry benchmark — see what discount rates are commonly used in your industry.
4. Personal judgment — experienced investors often adjust based on intuition; that’s okay.

The key: the discount rate should reflect your minimum acceptable return. Too high, and no project looks good; too low, and risk control is weak.

Quick Q&A

Q: If I can only choose one metric, VAN or TIR?
A: Choose VAN. It directly tells you how much real money you can make—that’s the ultimate question. TIR is more about efficiency.

Q: If both VAN and TIR look good, should I invest?
A: Yes. But also consider your risk appetite, capital availability, and investment goals. These indicators are necessary but not sufficient.

Q: Can I evaluate all projects with a fixed discount rate?
A: Not recommended. Projects with different risk levels should use different discount rates. Higher risk projects require higher rates.

Q: How to consider inflation when calculating VAN and TIR?
A: Two approaches: use inflation-adjusted nominal discount rates, or use real discount rates with real cash flows. Both methods should give consistent results if applied correctly.

Q: As an ordinary investor, do I need to calculate VAN and TIR myself?
A: Not necessarily by hand (software or apps are fine), but you must understand their meaning and limitations. Don’t be fooled by the numbers.

Final words

VAN and TIR are like the “left eye” and “right eye” of investment decision-making:

• VAN tells you how much real money you can earn (absolute value)
• TIR tells you how efficient the investment is (relative value)

Both are important, both have blind spots. Using them together gives a clearer picture.

True investment experts don’t rely solely on these two indicators. They also consider:

• ROI (Return on Investment)
• Payback period
• Risk metrics (potential losses)
• Market environment (big trends)
• Personal goals (quick gains or long-term stability)

Investing is like diagnosing a patient: VAN and TIR are just two items on the checklist. You need physical exams, medical history, and clinical experience to make a proper diagnosis. Don’t let numbers blind you.