# Questions tagged [calculation]

A generic tag to understand the calculations in a specific case. Please give out a sample illustration and ask a specific question. Ideally should also be accompanied by specific subject tags like "credit-cards", "savings-account", "index-funds" etc.

531 questions
Filter by
Sorted by
Tagged with
72k views

### 15 year mortgage vs 30 year paid off in 15

I've found similar questions, but they all seem to focus on a preexisting 30 year mortgage and whether or not it makes sense to refinance to a 15. My question is a bit different. I have not yet ...
• 923
140k views

### What is the correct answer for percent change when the start amount is zero dollars \$0?

Percent change is a very common calculation in finance. It helps us track growth. The formula is: [(y2 - y1)/y1] x 100 = percent change If the start period is \$0 (i.e. no money was made in the ...
50k views

### Should I pay an extra \$100 every month on my mortgage or pay \$1200 extra every year at the beginning of the year?

I can pay \$1200 extra once a year or \$100 every month - which is better? The first one does sound better, but for a 30 year mortgage, is it that significant? Say the mortgage is for \$200,000. ...
• 371
11k views

### Investor Paradox. How can you calculate how much is a company worth when buying part of it changes the total value?

I have a (probably very simple) question to which I haven't been able to wrap my head around. Say I have a company, and I am told that it is worth 1 USD (100% of the company). My friend, who has 1 USD,...
• 427
50k views

### Daily interest calculation combined with monthly compounding: Why do banks do this, and how-to in Excel?

I often see banks advertise (for accounts with fixed yearly interest, let's say 1.5%) – "interested is calculated daily, and compounded monthly". I have 2 questions: Why are they calculating ...
• 385
5k views

### 20% APR means only 10% interest? (UK)

I am trying to get better grasp of what the APR figure means, so this example is purely hypothetical. I have entered a loan of £100,000 into an APR calculator on MoneySuperMarket with a 20% APR for ...
• 343
18k views

### "Out of Pocket Maximum" and health insurance plan terminology & calculation?

I'm trying to understand the terminology on my health plan. I've read numerous websites, which have only confused me more, as they fail to use examples (more than one should be required) for people ...
• 639
4k views

### Why does the TD Bank principal portion of a mortgage payment go up and down in sawtooth? (why is interest payment on annuity in arrears non-monotonic)

I'm trying to understand the amortization schedules of TD mortgages, as produced by the TD Calculator. The monthly payment amounts (on this fixed rate mortgage) are predictable and constant, but the ...
• 511
47k views

### If I were to buy something a day before my due date for my credit card bill, would I be charged interest?

First of all, I am a resident of Canada. I am new to credit cards, so I hope my question makes sense. I've had my card for a few months ago and I've always paid the balance in full by the time the ...
• 189
9k views

### Is the Social Security retirement benefit calculation based on the last 40 quarters, or overall?

Are Social Security payouts based on the last 40 quarters, or overall earnings? That is: If the last 40 quarters of my working career are lower than these past 40 quarters worth, how does this affect ...
43k views

### How to determine contractor hourly rate and employee salary equivalents?

I am aware of the general differences between being an employee and being an independent contractor. However, I am unable to easily compare the two when it comes to after-tax compensation. Company A:...
• 283
62k views

### Calculate Future Value with Recurring Deposits

I am familiar with the formula for calculating FV and compound interest of a deposit, but I am wondering if there is a formula that will allow me to calculate how much money I will have after ...
• 151
3k views

### Should I pay off the credit cards now or do the monthly payments thing?

I have 3 credit cards with a total balance of about \$36k. Two of the cards are at 2% and the last one is at 0%. With the current payment structure, I'll be debt free in 25 months. I recently came ...
• 3,817
3k views

### How to calculate car insurance quote

I'm trying something in related to Auto Insurance and when I went through the State Farm's insurance portal, it asked me for a couple of questions like below. Vehicle ownership Car Age Person's Age ...
• 231
2k views

### Formula like Kelly criterion for choosing how much of an investment to liquidate?

I made a few investments, and surprise, surprise, a few of them shot up in value. Now I'm faced with the dilemma of the greedy: do I sell now and capitalize on existing profits, or do I wait, risking ...
• 1,383
3k views

### Does the history of credit utilization affect FICO score?

Most people are aware that the debt to credit limit ratio is a vital part of the FICO score. The FICO score is updated every time new information is received by the credit bureaus. However, is it ...
• 173
75k views

### If I earn 40 credits and stop working, would I get full Social Security benefits at age 67?

If I meet my 40 credit requirement in my 30s, and then left the States permanently and work at another country (and pay taxes there, not to the US), would I receive the full benefits when I become ...
16k views

### Why do mortgage affordability recommendations use gross income?

Whenever I see someone ask how to calculate how big a mortgage he can afford, the answer almost always comes back as a percentage of gross income. Why use gross income as the baseline? Why not net ...
5k views

### Paying extra on a mortgage. How much can I save? [duplicate]

Can I pay \$12,000 extra once a year or \$1000 every month - which option is better? The first option does sound better, but for a 30 year mortgage, is it that significant? The mortgage is for \$527,...
• 121
667 views

### How do I account for newly added money when computing my rate of return?

I have a simple spreadsheet where I track the balance in my investment account. What should I do to handle new deposits in the account? For example: End of Day 1: balance = \$100 End of Day 2: \$...
• 2,974
589 views

### What single metric is the ultimate measure of personal wealth? [closed]

More specifically, what is the single metric you would use to monitor personal wealth?
• 279
1k views

### Why didn't the balance go down on the student loan after a big check?

I owed about 45k on student loans. I wrote a check for around 10k to get the balance down. What I expected to happen was, for the balance to go down more than 10k, because that 10k would no longer ...
9k views

### Is there a term that better describes a compound annual growth rate (CAGR) when it is negative?

When calculating rates of return for an investment or portfolio over time, whether to report or compare performance, one frequently calculates the Compound Annual Growth Rate (CAGR). I've got a ...
• 31.7k
1k views

### Why might Social Security employee deductions from paycheck vary across pay periods?

What percentage of salary deducts for an employee's Social Security contribution? And why will there be a difference in % deducted? My salary statement for October and September 2015 has the same ...
• 111
1k views

### Calculate Income Tax amount of UK Salary

I've recently been trying to calculate different take home amounts from different salaries, and have ended up getting confused over how the different tax brackets work. If I try to calculate the ...
• 213
10k views

### At 3% inflation rate, is \$100 today worth \$40 20 years ago?

I'm little bit confused... At 3% inflation rate, is \$40 20 years ago worth \$100 today? Is it as simple as adding 60% of \$100 to get the worth of currency 20 years ago? Forgot about compound interest.....
• 135
4k views

### Overpaying on mortgage - How is term reduction calculated?

Just for some example figures: Original Term: 25 Years Loan Amount: £100,000 Interest rate: 2% I'm trying to make an excel table which keeps track of my mortgage payments including overpayments. ...
• 255
3k views

### For net worth, should I value physical property at my cost to replace it, or the amount I could get for selling it?

I recently was a good little consumer and picked up a relatively expensive set of new home furnishings, some furniture, a TV, some other electronics ... items of that nature (don't worry, been ...
• 1,573
620 views

### How do you go about calculating how much you need after retirement?

I am posting this question after reading this article on WSJ, where it says: Just 42% of working-age Americans have even tried to calculate what they will need in retirement, according to the ...
• 497
2k views

### How to determine new, lower interest payments after a lump sum mortgage payment, i.e. new amortization schedule?

Here's a financial math problem: I have a mortgage at about \$78,0000 with 5.5% interest and 56 of 360 monthly payments were made. I'm currently paying about \$360/month in interest charges. If I pay ...
• 829
3k views

### Continuous compounding in practice

A common explanation for the mathematical constant e (2.71828...) is that it is the factor by which an investment would grow at 100% interest rate over a period if it is continuously compounded. In ...
• 201
6k views

### Buying a more expensive house as a tax shelter (larger interest deduction)?

I've heard that some people buy a more expensive house as a tax shelter. In my simple mind I imaging the scenario: Pay 10,000 annual interest on the mortgage 50,000 annual income = 40,000 taxable ...
21k views

### Do I owe taxes if my deductions are higher than my income?

My total income this year was \$16,604 (wages, interest, and business income). My deductions (including IRA, personal exemption, standard deduction, and self employment tax) was \$17,404. TurboTax ...
20k views

### How do you do inflation calculations and estimates?

I'm an engineer, not an accountant so I have no idea what formulas to use (or even the proper terms to google for). I've looked around on a couple of google results, but most of the explanations just ...
• 341
72k views

### How do I calculate net monthly salary (after taxes) in Germany?

If I were to say that my yearly, gross salary was 50,000 euros, then what would be my monthly net after-tax income? For example, this calculator looks OK to me: http://calculatenetsalary.com/...
• 191
350 views

### Time, money and probability: Should i sell my electric bike

I bought a second hand electrical bike for a very reasonable price (600 euro) more than a year ago. Since then i changed jobs and i now commute by car and the bike just sits in the shed. If I sell it ...
• 193
1k views

### Is there a dollar amount that, when adding Massachusetts Sales Tax, precisely equals \$200?

I am confused about calculating Massachusetts Sales Tax (6.25%). Is there such an amount, that when added to its sales tax, equals \$200? The reason I ask is because my business has been charging \$...
981 views

### How does compounding of annual interest work?

I have tried reading up on it, but I just find it confusing. Apparently, if you started investing \$150/month at a 15% annual return and kept reinvesting the profits, here is what you would have ...
• 1,671
456 views

### How much is enough to save as a rainy-day fund before I start plugging my higher-interest student loans?

Typically, what is considered realistic? 6 months expenses? A year? I understand this is more of an "opinion" question but I am still curious what people think is a responsible buffer (in the event of ...
• 365
3k views

### What is the formula for calculating the total cost of a loan with extra payments towards the principal?

If I have a 30 year mortgage of \$200,000 with an APR of 4.446% I can calculate how much my monthly payment will be and how much the total cost of the loan will be. But what if I have an extra \$200 to ...
33k views

### What is the formula for the monthly payment on an adjustable rate mortgage?

Can people tell me how monthly payments are calculated when a mortgage has an initial rate? What is the formula? I have seen online calculators but not formulae. My guess is: We assume that the ...
• 193
14k views

### In the event of a corporate spin-off, how can I calculate the correct cost basis for each company's shares?

Consider this example: Siemens is going to have a spin-off (next Monday). If I owned, say, 10,000 shares of Siemens bought at an average price of 80 euros, my cost would be 800,000 euros. In the ...
• 289
2k views

### Am I doing the math for this covered call/long put strategy correctly? What risks do I run with this strategy?

In this trade, I write an in-the-money covered call and buy an in-the-money put (as an example) on GM, expiring in September 2014. The call premium is \$10.02 with a strike of \$26, and the put premium ...
• 1,958
5k views

### How can I calculate a "running" return using XIRR in a spreadsheet?

I should say that I'm not married to XIRR, I just want to calculate the return on a running basis in a column next to dates, deposits and balances. Here's a screenshot of a simplified spreadsheet in ...
• 10k
294 views

### Help understanding credit card interest

I have a credit card with an outstanding balance and I am trying to work out when I will complete paying it off. It is a UK credit card (where I am based) and I do not spend on it. I pay 150 per ...
• 183
1k views

### Credit card interest calculator with grace period & different interest rate calculation methods?

Is there an (ideally online) credit card interest calculator that includes grace periods and lets you choose the interest calculation method (eg, "adjusted balance", "average daily balance", "two-...
5k views

### Would the minimum payment or full CC amount be considered monthly debt?

Based on Is rent considered a debt? The question of: What is your total monthly debt payment (e.g. student loans, vehicles, credit cards, personal loans, etc.)? got me thinking. If you rack up \$...
• 8,473
3k views

### What does "not funded by you" mean in Vanguard's college savings planner?

What does the green area called "Not funded by you" represent in this type of college 529 calculator? Source calculator here.
• 213
3k views

### What is the "rule of 70" or "rule of 72" with regards to investment, and how do I apply it?

What is the "rule of 72" (sometimes called the "rule of 70") with regards to investment, and how do I apply it?
• 962