Net Present Value (NPV)

By JASON FERNANDO

Updated December 22, 2023

Reviewed by JULIUS MANSA

Fact checked by PETE RATHBURN

净现值

作者：JASON FERNANDO

更新时间：2023年12月22日

审阅人：JULIUS MANSA

事实核查人：PETE RATHBURN

 

What Is Net Present Value (NPV)?

什么是净现值（NPV）？

 

Net present value (NPV) is the difference between the present value of cash inflows and the present value of cash outflows over a period of time. NPV is used in capital budgeting and investment planning to analyze the profitability of a projected investment or project.

净现值（NPV）是一段时间内现金流入的现值和现金流出的现值之间的差额。净现值用于资本预算和投资规划，以分析预计投资或项目的盈利能力。

 

NPV is the result of calculations that find the current value of a future stream of payments using the proper discount rate. In general, projects with a positive NPV are worth undertaking, while those with a negative NPV are not.

净现值是使用适当的贴现率计算未来支付流的当前价值的结果。一般来说，净现值为正的项目值得开展，而净现值为负的项目则不值得开展。

 

KEY TAKEAWAYS

文章要点

 

Net present value (NPV) is used to calculate the current value of a future stream of payments from a company, project, or investment.

净现值被用于计算公司、项目或投资的未来支付流的现值。

To calculate NPV, you need to estimate the timing and amount of future cash flows and pick a discount rate equal to the minimum acceptable rate of return.

计算净现值时，需要估计未来现金流的时间和金额，并选择一个等于最低可接受回报率的贴现率。

The discount rate may reflect your cost of capital or the returns available on alternative investments of comparable risk.

贴现率可能会反映你的资本成本或可比风险的替代投资的回报。

If the NPV of a project or investment is positive, it means its rate of return will be above the discount rate.

如果一个项目或投资的净现值为正，这意味着它的回报率将高于贴现率。

 

Net Present Value (NPV) Formula

净现值公式

 

If there’s one cash flow from a project that will be paid one year from now, then the calculation for the NPV of the project is as follows:

如果某一项目的某一现金流将在一年后支付，那么该项目的净现值计算方式如下：

 

where:

i=Required return or discount rate

t=Number of time periods

其中：

i=要求的回报或贴现率

t=时段数

 

If analyzing a longer-term project with multiple cash flows, then the formula for the NPV of the project is as follows:

如果是分析一个具有多个现金流的长期项目，那么该项目的净现值公式如下：

 

 

where:

Rt=net cash flow-outflows during a single period t

i=discount rate or return that could be earned in alternative investments

t=number of time periods

其中：

Rt=现金流量净额-单一时段t期间的流出

i=替代投资可获得的贴现率或回报

t=时段数

 

If you are unfamiliar with summation notation, here is an easier way to remember the concept of

NPV=Today’s value of the expected cash flows−Today’s value of invested cash

若您不熟悉求和符号，还有一个更简单的方法帮您记忆：

净现值=预期现金流量的当日价值-投资现金的当日价值

 

What NPV Can Tell You

净现值可以告诉你什么

 

NPV accounts for the time value of money and can be used to compare the rates of return of different projects or to compare a projected rate of return with the hurdle rate required to approve an investment. The time value of money is represented in the NPV formula by the discount rate, which might be a hurdle rate for a project based on a company’s cost of capital. No matter how the discount rate is determined, a negative NPV shows that the expected rate of return will fall short of it, meaning that the project will not create value.

净现值说明的是货币的时间价值，可用于比较不同项目的回报率，或将预计回报率与批准投资所需的最低回报率进行比较。货币的时间价值在净现值公式中由贴现率表示，贴现率可能是基于公司资本成本的项目的最低回报率。无论贴现率如何确定，负的净现值表明将达不到预期回报率，意味着项目不会创造价值。

 

In the context of evaluating corporate securities, the net present value calculation is often called discounted cash flow (DCF) analysis. It’s the method used by Warren Buffett to compare the NPV of a company’s future DCFs with its current price.

在评估公司证券时，净现值计算通常被称为贴现现金流分析。这是沃伦·巴菲特用来比较一家公司未来贴现现金流的净现值与其当前价格的方法。

 

The discount rate is central to the formula. It accounts for the fact that, as long as interest rates are positive, a dollar today is worth more than a dollar in the future. Inflation erodes the value of money over time. Meanwhile, today’s dollar can be invested in a safe asset like government bonds; investments riskier than Treasurys must offer a higher rate of return. However it’s determined, the discount rate is simply the baseline rate of return that a project must exceed to be worthwhile.

贴现率是公式的核心。它说明了这样一个事实，即只要利率是正的，今天的一美元就比未来的一美元更有价值。随着时间的推移，通货膨胀会侵蚀货币的价值。与此同时，今天的美元可以投资于政府债券等安全资产；比美国国债风险更高的投资必须提供更高的回报率。无论如何确定，贴现率都只是一个项目必须超过才有价值的基线回报率。

 

For example, an investor could receive $100 today or a year from now. Most investors would not be willing to postpone receiving $100 today. However, what if an investor could choose to receive $100 today or $105 in one year? The 5% rate of return might be worthwhile if comparable investments of equal risk offered less over the same period.

例如，一个投资者可能会在今天或一年之后收到100美元。大多数投资者不会愿意推迟收到100美元。但是，如果投资者可以选择今天获得100美元或一年之后获得105美元呢？如果同等风险的可比投资在同一时期可提供的回报更少，那么5%的回报率则可能是值得的。

 

If, on the other hand, an investor could earn 8% with no risk over the next year, then the offer of $105 in a year would not suffice. In this case, 8% would be the discount rate.

另一方面，如果一个投资者在接下来的一年里可以在没有风险的情况下获得8%的收益，那么一年105美元的报价则是不够的。在这种情况下，贴现率为8%。

 

Positive NPV vs. Negative NPV

正净现值和负净现值

 

A positive NPV indicates that the projected earnings generated by a project or investment—discounted for their present value—exceed the anticipated costs, also in today’s dollars. It is assumed that an investment with a positive NPV will be profitable.

正净现值表明某一项目或投资产生的预期收益——按其现值贴现——超过预期成本（同样以今天的美元计算）。人们认为，拥有正净现值的投资为可获利的投资。

 

An investment with a negative NPV will result in a net loss. This concept is the basis for the net present value rule, which says that only investments with a positive NPV should be considered.

净现值为负的投资会导致净亏损。这一概念是净现值规则的基础，该规则认为只有净现值为正的投资才应被予以考虑。

 

Limitations of NPV

净现值的局限性

 

A notable limitation of NPV analysis is that it makes assumptions about future events that may not prove correct. The discount rate value used is a judgment call, while the cost of an investment and its projected returns are necessarily estimates. The NPV calculation is only as reliable as its underlying assumptions.

净现值分析的一个显著局限性是，它对未来事件做出的假设可能不正确。使用的贴现率值属主观判断，因而投资成本及其预期回报必然是估计值。净现值计算的可靠性取决于其基本假设。

 

The NPV formula yields a dollar result that, though easy to interpret, may not tell the entire story. Consider the following two investment options: Option A with an NPV of $100,000, or Option B with an NPV of $1,000.

净现值公式会计算得出一个美元金额，这一金额尽管很容易解释，但可能无法反映全貌。考虑一下以下两个投资选项：选项A，净现值为100,000美元，或选项B，净现值为1,000美元。

 

NPV Formula

净现值公式

 

Pros

优点

 

Considers the time value of money

Incorporates discounted cash flow using a company’s cost of capital

Returns a single dollar value that is relatively easy to interpret

May be easy to calculate when leveraging spreadsheets or financial calculators

考虑到了货币的时间价值

纳入使用公司资本成本计算的贴现现金流

得到的是相对容易解释的单一美元金额值

使用电子表格或财务计算机时很容易计算

 

Cons

缺点

 

Relies heavily on inputs, estimates, and long-term projections

Doesn’t consider project size or return on investment (ROI)

May be hard to calculate manually, especially for projects with many years of cash flow

Is driven by quantitative inputs and does not consider nonfinancial metrics

严重依赖输入信息、估计和长期预测

未将项目规模或投资回报考虑在内

很难手动计算，特别是对于拥有多年现金流的项目而言

由定量输入驱动，未考虑非财务指标

 

What Does Net Present Value (NPV) Mean?

净现值指的是什么？

 

Net present value (NPV) is a financial metric that seeks to capture the total value of an investment opportunity. The idea behind NPV is to project all of the future cash inflows and outflows associated with an investment, discount all those future cash flows to the present day, and then add them together. The resulting number after adding all the positive and negative cash flows together is the investment’s NPV. A positive NPV means that, after accounting for the time value of money, you will make money if you proceed with the investment.

净现值是一个财务指标，旨在体现投资机会的总价值。净现值背后的理念是预测与投资相关的所有未来现金流入和流出，将所有这些未来现金流贴现到今天，然后将它们相加。将所有正负现金流相加后得到的数字就是投资的净现值。正的净现值意味着，在考虑了货币的时间价值后，如果你继续投资，你就会赚钱。

 

What Is a Good NPV?

净现值为多少算好？

 

In theory, an NPV is “good” if it is greater than zero. After all, the NPV calculation already takes into account factors such as the investor’s cost of capital, opportunity cost, and risk tolerance through the discount rate. And the future cash flows of the project, together with the time value of money, are also captured. Therefore, even an NPV of $1 should theoretically qualify as “good,” indicating that the project is worthwhile. In practice, since estimates used in the calculation are subject to error, many planners will set a higher bar for NPV to give themselves an additional margin of safety.

理论上，如果净现值大于零，它就是“好的”。毕竟，净现值的计算已经通过贴现率考虑了投资者的资本成本、机会成本和风险承受能力等因素。并且项目的未来现金流，连同货币的时间价值，也有体现。因此，即使净现值为1美元，理论上也应该被视为“好的”，表明该项目是值得的。在实践中，由于计算中使用的估计值容易出错，许多规划者会为净现值设定更高的标准，以给自己一个额外的安全边际。

 

Why Are Future Cash Flows Discounted?

为什么未来现金流要贴现？

 

NPV uses discounted cash flows to account for the time value of money. As long as interest rates are positive, a dollar today is worth more than a dollar tomorrow because a dollar today can earn an extra day’s worth of interest. Even if future returns can be projected with certainty, they must be discounted for the fact that time must pass before they’re realized—time during which a comparable sum could earn interest.

净现值使用贴现现金流计算货币的时间价值。只要利率为正，今天的一美元就比明天的一美元更有价值，因为今天的一美元可以额外赚取一天的利息。即使未来的回报可以被肯定的预测，它们也必须贴现，因为它们在实现之前必须经过一段时间——在这段时间内，是可以赚取一笔可比利息的。