Present Value of Annuity — калькулятор приведённой стоимости выплат
Quick Guide: введите размер периодического платежа, процентную ставку, срок аннуитета, частоту платежей и частоту начисления процентов, чтобы посчитать present value серии одинаковых будущих cash flows. Подходит для пенсий, лотерейных annuity, structured settlements, оценки лизинга/аренды и расчётов по займам.
Что такое annuity?
Annuity — это серия одинаковых платежей через фиксированные интервалы в течение заданного периода. Annuities — базовое понятие в финансовом планировании и встречается в разных ситуациях:
- Retirement planning: пенсии, выплаты 401(k), Social Security
- Insurance: страховые взносы, annuity contracts
- Investments: купоны облигаций, потоки дивидендов
- Loans: ипотека, автокредиты, student loans
- Real estate: арендные платежи, land contracts
- Lottery winnings: ежегодные выплаты по лотерее
Две ключевые характеристики annuity:
- Equal payments: каждый платеж одинаковый
- Fixed intervals: платежи происходят регулярно, по заранее известному графику
Что такое present value of annuity?
Present value of annuity (PVA) — текущая стоимость всех будущих платежей, приведённая по заданной процентной ставке. Идея основана на принципе time value of money: доллар сегодня “ценнее” доллара завтра, потому что его можно инвестировать и получить доход.
Расчёт present value отвечает на вопросы вроде:
- сколько стоит сегодня пенсия $2,000 monthly на 20 лет?
- какова текущая стоимость лотерейной annuity $1 million annually на 30 лет?
- что выгоднее: $500,000 сейчас или $50,000 в год 15 лет?
- сколько стоит объект аренды, если он даёт $2,000/month 25 лет?
Виды annuity
Платежи происходят в конце каждого периода. Это самый распространённый тип.
Examples:
- Mortgage payments (paid at end of month)
- Car loan payments
- Student loan payments
- Bond coupon payments
Timeline: Period 1 → Payment 1 | Period 2 → Payment 2 | Period 3 → Payment 3
Платежи происходят в начале периода. Так как каждый платеж приходит на один период раньше, annuity due имеет более высокий present value, чем ordinary annuity.
Examples:
- Rental lease payments (typically paid in advance)
- Insurance premiums
- Lottery payouts (if paid at start of year)
- Subscription services
Timeline: Payment 1 → Period 1 | Payment 2 → Period 2 | Payment 3 → Period 3
Платежи растут постоянным темпом каждый период. Такой вариант учитывает инфляцию или рост затрат.
Examples:
- Inflation-adjusted pension payments
- Salary increases with cost-of-living adjustments
- Rental payments with built-in annual increases
Note: для этого типа используйте поле growth rate.
Annuity, которая длится бесконечно. Формула упрощается до: PV = PMT / i
Examples:
- Preferred stock dividends
- Endowment funds
- Consols (perpetual bonds)
Формулы annuity
Формула ordinary annuity
PVA = PMT × [(1/i) - (1/(i × (1+i)^n))]
Where:
- PVA = present value of annuity
- PMT = платеж за период
- i = периодическая ставка (annual rate / compounding frequency)
- n = число платежей (years × payment frequency)
Формула annuity due
PVA = PMT × [(1/i) - (1/(i × (1+i)^n))] × (1+i)
Формула annuity due — это ordinary annuity, умноженная на (1+i), потому что платежи происходят на один период раньше.
Формула growing annuity (g ≠ i)
PVA = [PMT / (i - g)] × [1 - ((1+g)/(1+i))^n]
Where:
- g = growth rate (годовой темп роста платежей)
Формула growing annuity (g = i)
PVA = PMT × n / (1+i)
Частный случай, когда growth rate равен interest rate.
Continuous compounding
PVA = [PMT / (e^r - 1)] × [1 - 1/e^(r×t)]
Где e ≈ 2.718 (число Эйлера), а r — annual interest rate.
Detailed Calculation Examples
Example 1: Ordinary Annuity (Pension Plan)
Scenario: You're offered a pension that pays $7,000 annually for 4 years. The interest rate is 5%. What is this pension worth today?
Given:
- PMT = $7,000
- r = 5% = 0.05
- n = 4 years
- Type: Ordinary annuity
Calculation:
PVA = $7,000 × [(1/0.05) - (1/(0.05 × (1.05)^4))]
PVA = $7,000 × [20 - (1/(0.05 × 1.2155))]
PVA = $7,000 × [20 - 16.454]
PVA = $7,000 × 3.546
PVA = $24,822
Result: The pension is worth $24,822 in today's dollars. This is less than $28,000 (4 × $7,000) due to the time value of money.
Example 2: Annuity Due (Rent Payments)
Scenario: A commercial property lease requires $10,000 monthly payments for 5 years, paid at the beginning of each month. With a 6% annual interest rate, what's the present value?
Given:
- PMT = $10,000
- r = 6% annual = 0.06
- t = 5 years
- Payment frequency: Monthly (12 times/year)
- n = 5 × 12 = 60 payments
- i = 0.06/12 = 0.005 per month
- Type: Annuity due
Step 1 - Calculate Ordinary Annuity:
PVA(ordinary) = $10,000 × [(1/0.005) - (1/(0.005 × (1.005)^60))]
PVA(ordinary) = $10,000 × 51.726
PVA(ordinary) = $517,260
Step 2 - Adjust for Annuity Due:
PVA(due) = $517,260 × (1 + 0.005)
PVA(due) = $519,846
Result: The lease is worth $519,846 today. Note that the annuity due is worth $2,586 more than an ordinary annuity because payments are received earlier.
Example 3: Growing Annuity (Inflation-Adjusted Pension)
Scenario: A pension starts at $50,000 annually and increases by 3% each year for 20 years. The discount rate is 7%. What's the present value?
Given:
- PMT = $50,000 (first payment)
- r = 7% = 0.07
- g = 3% = 0.03 (growth rate)
- n = 20 years
Calculation (g ≠ i):
PVA = [$50,000 / (0.07 - 0.03)] × [1 - ((1.03/1.07)^20)]
PVA = [$50,000 / 0.04] × [1 - (0.9626)^20]
PVA = $1,250,000 × [1 - 0.4564]
PVA = $1,250,000 × 0.5436
PVA = $679,500
Result: The growing pension is worth $679,500 today, significantly more than a constant $50,000 annuity would be worth.
Understanding the Components
The fixed amount paid or received each period. This remains constant throughout the annuity life (unless it's a growing annuity).
Examples:
- $1,000 monthly mortgage payment
- $50,000 annual pension payment
- $500 quarterly dividend payment
The annual rate used to discount future payments back to present value. This represents your required rate of return or opportunity cost of capital.
How to choose:
- Use current market interest rates for similar investments
- Consider inflation (real vs. nominal rates)
- Account for risk (higher risk = higher discount rate)
- Use your personal required return rate
How often payments are made:
- Annual: Once per year (q = 1)
- Semi-annual: Twice per year (q = 2)
- Quarterly: Four times per year (q = 4)
- Monthly: Twelve times per year (q = 12)
More frequent payments generally result in higher present values because money is received sooner.
How often interest is calculated and added to the principal:
- Annual: Once per year (m = 1)
- Semi-annual: Twice per year (m = 2)
- Quarterly: Four times per year (m = 4)
- Monthly: Twelve times per year (m = 12)
- Continuous: Theoretical limit (m = ∞), uses e^r formula
More frequent compounding increases the present value slightly due to more precise discounting.
Practical Applications
1. Retirement Planning
Determine how much you need to save today to fund a desired retirement income stream.
Question: You want to receive $5,000 monthly for 30 years in retirement. How much do you need in your retirement account today (assuming 6% annual return)?
Solution: Use our calculator with PMT=$5,000, r=6%, t=30, frequency=monthly, type=ordinary
Answer: Present Value ≈ $830,000
2. Loan Evaluation
Calculate the current value of loan payments to determine fair loan amounts.
Question: A borrower will pay you $1,200 monthly for 5 years. At 8% interest, how much should you lend?
Solution: PMT=$1,200, r=8%, t=5, frequency=monthly
Answer: Present Value ≈ $59,318 (maximum loan amount)
3. Structured Settlement Comparison
Compare a lump sum offer vs. periodic payments.
Question: You're offered either $500,000 now or $40,000 annually for 15 years. Which is better at 5% interest?
Solution: Calculate PVA of $40,000/year at 5% for 15 years
Answer: PVA ≈ $415,460. The lump sum is better!
Key Differences: Ordinary Annuity vs. Annuity Due
| Characteristic | Ordinary Annuity | Annuity Due |
|---|---|---|
| Payment Timing | End of period | Beginning of period |
| Present Value | Lower | Higher (by factor of 1+i) |
| Examples | Mortgages, car loans, bonds | Rent, insurance, lottery |
| Formula Adjustment | Standard formula | Multiply by (1+i) |
How to Use This Calculator
- Select Currency: Choose your currency (USD, EUR, etc.)
- Enter Payment Amount: The fixed payment per period
- Set Interest Rate: Annual discount rate or required return
- Enter Term: Total duration in years
- Choose Payment Frequency: How often payments occur
- Select Compounding Frequency: How often interest compounds
- Pick Annuity Type: Ordinary (end) or Due (beginning)
- Optional Growth Rate: For payments that increase over time
- Calculate: See your present value instantly
Understanding the Results
Our calculator provides:
- Present Value of Annuity: Current worth of all future payments
- Total Future Payments: Sum of all payments (PMT × n)
- Total Discount: Difference between future payments and present value
- Number of Periods: Total number of payments
- Periodic Interest Rate: Interest rate per compounding period
Frequently Asked Questions
Due to the time value of money. A dollar today is worth more than a dollar in the future because you can invest today's dollar and earn returns. The present value discounts future payments to reflect this opportunity cost.
When i = 0%, the present value equals the sum of all payments (PMT × n). This makes sense because without discounting, future money is worth the same as present money.
Not necessarily. In practice, they often differ. For example, you might make monthly loan payments while interest compounds daily. Our calculator handles any combination of frequencies correctly by converting to periodic rates.
Check when payments are made. If payment is due before receiving the benefit (rent, insurance), use annuity due. If payment comes after the period (mortgage interest, loan payments), use ordinary annuity. When in doubt, check the contract terms.
PV of annuity calculates the value of equal periodic cash flows. Net Present Value (NPV) is more general and can handle unequal cash flows, including an initial investment (negative cash flow). NPV = -Initial Investment + PV of all future cash flows.
No. This calculator is specifically for annuities where all payments are equal. For irregular cash flows, you need to discount each payment individually or use an NPV calculator. However, you can use the growing annuity option if payments increase by a constant percentage.
Use your required rate of return or opportunity cost. For pension valuations, use current annuity rates (4-6%). For investment decisions, use your expected return rate. For loan decisions, use current market lending rates. Consider inflation for real vs. nominal calculations.
Continuous compounding is the theoretical limit where interest is calculated and added infinitely often (m → ∞). It uses the mathematical constant e (≈2.718). While unrealistic, it provides a useful upper bound and is used in some advanced financial models. The difference from daily compounding is typically negligible.
Comparing Present Values
Same annuity ($1,000/month for 10 years, 6% interest) under different conditions:
| Scenario | Present Value |
|---|---|
| Ordinary Annuity, Annual Compounding | ~$90,074 |
| Ordinary Annuity, Monthly Compounding | ~$90,074 |
| Annuity Due, Monthly Compounding | ~$90,523 |
| Growing Annuity (2% growth), Monthly | ~$99,856 |
Common Mistakes to Avoid
- Mixing nominal and real rates: Use consistent rates (both nominal or both inflation-adjusted)
- Wrong annuity type: Verify whether payments are at beginning or end of period
- Incorrect frequency conversion: Ensure you're using the right periodic rate
- Forgetting about taxes: Present value calculations are typically pre-tax
- Ignoring growth: If payments increase annually, use the growing annuity formula
Important Notes
- This calculator provides theoretical present values based on mathematical formulas
- Actual market prices for annuities may differ due to fees, credit risk, and supply/demand
- Results don't account for taxes, which can significantly impact after-tax values
- For growing annuities, ensure growth rate is sustainable and realistic
- Always consult with qualified financial advisors for major financial decisions
- This tool is for educational and planning purposes only