How is your credit score related to credit utilization?
"1 - yes, it's fine to pay in full and it helps your score. 2 - see chart above, it's calculated based on what the bill shows each month.  3 - answered by chart. 1-19% utilization is ideal. 0% is actually worse than 41-60% Note: The above image was from Credit Karma. A slightly different image appears at the article The Relationship Between Your Credit Score and Credit Card Utilization Rate. I don't know how true this really is. Since writing this answer, I've seen offers of a true ""FICO score"" from multiple credit cards, and have tinkered with my utilization. I paid my active cards before the reporting date, and saw 845-850 once my utilization hit 0. Credit Karma still has me at 800." "Curious, why are you interested in building/improving your credit score? Is it better to use your card and pay off the bill completely every month? Yes. How is credit utiltization calculated?    Is it average utilization over the month, or total amount owed/credit_limit per month? It depends on how often your bank reports your balances to the reporting agencies. It can be daily, when your statement cycle closes, or some other interval. How does credit utilization affect your score?  Closest to zero without actually being zero is best. This translates to making some charges, even $1 so your statement shows a balance each statement that you pay off. This shows as active use. If you pay off your balance before the statement closes, then it can sometimes be reported as inactive/unused. Is too much a bad thing?  Yes. Is too little a bad thing? Depends. Being debt free has its advantages... but if your goal is to raise your credit score, then having a low utilization rate is a good metric. Less than 7% utilization seems to be the optimal level.  ""Last year we started using a number, not as a recommendation, but as a fact that most of the people with really high FICO scores have credit utilization rates that are 7 percent or lower,"" Watts said. Read more: http://www.bankrate.com/finance/credit-cards/how-to-bump-up-your-credit-score.aspx Remember that on-time payment is the most important factor. Second is how much you owe. Third is length of credit history. Maintain these factors in good standing and you will improve your score: http://www.myfico.com/CreditEducation/WhatsInYourScore.aspx"
This very much depends how you use that second line of credit and what your current credit is. There are of course many more combinations buy you can probably infer the impact based on these cases.   Your credit score is based on your likely hood of being profitable to a creditor should they issue you credit. This is based on your history of your ability to manage your credit.  Having more credit and managing it well shows that you have a history of being responsible with greater sums of money available.  If you use the card responsibly now then you are more likely to continue that trend than someone with a history of irresponsibility.  Having a line but not using it is not a good thing.  It costs the creditor money for you to have an account.  If you never use that account then you are not showing that you can use the account responsibly so if you are just going to throw the card in a safe and never access it then you are better off not getting the card in the first place. "First I want to be sure Op understands how ""Credit Utilization"" is scored as this confuses many folks here in the US.  There is no ""reward"" for charging money or carrying balances, only penalty.  If you have one credit card with a $10,000 limit and owe $8,000  you have an 80% utilization which will signal to banks that you are having financial difficulties.  (Anything over 30% on a single card is usually penalized significantly.)  The ideal utilization is something around 0, which is in the ballpark of the 5% Op mentioned.  Again there is never any direct benefit to your credit of spending a penny on any of your credit cards.*   Banks offer the best rates to people that pay off their balances each month or don't use their cards in the first place.  Why? Despite the system being imperfect in many ways, utilization is a good indicator.  Example: If you have a card with a  $10,000 limit and pay it off every month that speaks to you being a good risk. If you compared this person to the person above, who do you think would be the most likely to pay back a car loan? Finally, Utilization is a small part of the credit score.  I would call it more of a ""hurdle"" than a factor, at least concerning good rates and approvals.  Most of your credit, is based on length of history, paying on time, and having multiple types of credit. Real life example: I had a relative that had perfect payment history for decades.  They got divorced and started accumulating a balance.  The person got other cards with 0% apr to avoid the interest, but their balance only grew.  -They had to use the card to make ends meet, etc.  (3 kids, single parent)  They ended up filing a sizable bankruptcy a few years later.  This was one of the most responsible people I've ever known.  (Yes that statement will seem far fetched to someone else.  It was almost impossible to get them to file bankruptcy, even though there was no way to ever pay the money back.) The point?  Utilization shows a more 'current' picture than some of the other portions due.  -  Had those banks used the high utilization as a warning sign they would have saved a lot of money.   A 'fun' way of looking at credit: Sometimes I describe credit score as a popularity contest.  If you really 'need' money banks are not going to help you.  However if your credit shows everyone is lining up to loan you money, other banks are going to want in too.  ""Banks only make loans to people that don't need them."" *** Spending a lot on Credit Cards does sometimes have the indirect effect of getting balance increases that could have a slight increase in your score.  This happens  less than it did prior to the financial fiasco.  Also the effect of this is on the score negligible unless carrying a balance.  ( And the person carrying a balance also has a lower score anyways.)  Additionally someone charging less could probably get a similar raise if they asked for it.  (Raises vary greatly by issuer.))" Your credit score, for better or worse, is increasingly about more than just getting loans. For example insurance companies can use it to some extent to determine your rates,. Credit cards are meant to be used so generally it doesn't hurt your credit score to use them.  To top it off you even get an interest grace period so you don't have to rush home and pay balances as soon as they're charged.   In general you accrue charges during your statement period, we'll call it September 1 through September 30.  The statement due date is something like 20 days after the close of the statement period, so we'll call it October 20.  As long as you habitually pay your entire statement balance by the due date you will never pay interest.  You charge your laptop on September 3, it shows up on your statement as $1,300, you pay $1,300 on October 18, you pay no interest. However, if you pay $1,000 on October 18 leaving a $300 balance to be carried in to the next statement period (a carried balance) you will pay interest.  Generally interest is calculated based on your average daily balance during the statement period, which is now be the October 1 to October 31 period.  You'll notice that you didn't pay anything until the October 18, that means the entire $1,300 will be included in your average daily balance up to the 18th of the month.  Add to that, anything else you charge on the card now will be included in your average daily balance for interest charge calculation purposes. The moral of the story is, use your card, and pay your entire statement balance before the due date.   Now how much will this impact your credit score?  It's tough to say.  Utilization is not a bad thing until it's a big number.  I've read that 70% utilization and over is really the point at which lenders will raise an eyebrow and under 30% is considered excellent. If you have one card and $1,300 is a significant portion of your available limit, then yes you should probably pay it down quickly.  Spend six or so months using the card and paying it, then call your bank and ask for a credit line increase. Assuming you are asking about a credit score in the United States, the following applies. To find out your FICO score, navigate to AnnualCreditReport, the official site to help consumers receive their credit report from each of the three organizations providing these scores - Equifax, Experian, and TransUnion.  You are - in many states - entitled to a free copy of your credit report from each of these organizations annually.   This copy of your credit report will not contain your credit score from that organization.  It will, however, contain information that goes into your credit score - the lines of credits on file, any delinquencies reported, etc. If you decide you would like to pay for your credit score from each bureau, you will have the option to receive this information while getting your credit report, but you will have to pay a nominal fee for it.  Remember that each of the 3 bureaus gives you a different score.  Averaging your 3 scores should give you a good idea of your FICO score.  Note that your report is far more important than your score - once you know that, you know if you're in a good place or not. These other questions are so close that they might even be considered duplicates, and provide other suggestions for how to check your score. As a warning, don't trust the many ads out there saying you can get your score for free.  Only AnnualCreditReport is considered a safe place for entering the very personal information required to get a score.  The FTC backs this up. "Having no utilization makes you an outlier, it's an unusual circumstance for most people, and the scoring model cannot make any predictions based on it. If you think of it from the underwriter's perspective, zero utilization could mean all sorts of things... are you dead? indigent? unable to work?  When you buying a product (like money or insurance) whose pricing is based on risk, being ""weird"" will usually make you a higher risk. That said, it isn't the end of the world. If you are in this situation, I wouldn't lose sleep over it." Credit scores have a huge financial impact on consumers, even though most people don’t know how they are calculated or which bad habits may be driving theirs down. Your credit score is a number on a scale of 300 to 900 that can affect all of your financial decisions, from shopping for groceries to applying for a mortgage. Read on to find out why a good credit rating is so important. 4 Things to Know About Your Credit Score Why it’s important. Throughout your life, you will probably rely on your credit to acquire the items that you want and need but can’t necessarily pay cash for. Each time you buy something on credit, merchants are taking a gamble on you; the bet is IIRC it's not a FICO score, as mentioned here, too. That said, apart from borrowing money to optimise your credit score as a hobby, my understanding is that once you're above a FICO score of 750, it pretty much doesn't matter how close to 800 you get. Absolutely. It's the way credit is calculated. The most important things here are credit utilization (how much of your open credit you're using, the less the better for your score) and and length of open credit. The longer you've had a credit card, the more it helps your score. If you use your card and pay it off before the bill comes, the credit card company still knows you're using the card and won't close it. I recommend you download credit karma so you can track your score and learn more about how credit is calculated. "Credit Scores / Rates are based on sometimes simple and sometimes quite complex Statistical Models (Generalised Linear Models, Neural Networks, Regression and Classification Trees, Mixture Models, etc).This depends on whether it is something more general like FICO or what large banks develop in-house. In any case, there are many legislation-dependent factors (Qualitative such as education, occupation security, sex, etc, payment history; or Quantitative such as age, liquidity and leverage ratios, etc).  Now, most model that are used today are propriety and closely held trade secrets. The most important reason for this is actually because of the databases that feed the models. More better quality data is what makes the real difference ... although at the cutting-edge, the mathematicians/statisticians/computer scientists that design the algorithms will make a huge difference.  Now, back to the main thing: The Credit Score/Rate is meant to be used only as an indicator for representing the Probability of Default (""How likely you are to default on your obligation towards me?"" is what it means and that is largely based upon ""Has company/he/she honoured his financial obligations?"") of a certain consumer. In more sophisticated models, they may also use your industry sector or occupational and financial security to predict the future behaviour. However, this ""Credit Score"" has meaning only in relation to a ""Credit Limit"" (""Can you pay back my $X?""). The credit limit on the other hand is defined by your income level, debt/asset, etc).   As a credit risk analyst, whether we are dealing with large corporate loans, mortgages, personal loans, etc), the principles are the same: One thing to consider is that factors considered in determining a credit score usually do not have a simple linear relationship.  Consumer Profile types such as utilisation rate are a lot more about EFFECT than CAUSE:   The most important thing is to honour your obligations, whether you pay before or after you spend makes little difference, so long as you pay in full and prior to maturity, your rate/score will improve with time. Financial Institutions have many ways to make money of everyone. Some, such as interest rates and fees are directly charged to you and some are charged to your goods-and-services providers. That has no bearing on your score. Sometimes it even makes sense to take on customers with rock-bottom ratings, lend them lots of money, and charge them to dirt. As you may well know, the recent financial crisis - with ongoing after-shocks and tremors - was the result of such practices." I guess we opt in when we take out credit, or if you sign a lease or anything like that. While credit reporting is the backbone of consumer finance, im not sure exactly how it works, and this may not be the right sub. r/personalfinance may be better. If you get a good answer elsewhere I would be much obliged if you posted it back here. I think you got the message mixed up a little: Racking up big balances can hurt your scores, regardless of whether you pay your bills in full each month.   What's typically reported to the credit bureaus, and thus calculated into your scores, are the balances reported on your last statements. (That doesn't mean paying off your balances each month isn't financially smart -- it is -- just that the credit scores don't care.)   You typically can increase your scores by limiting your charges to 30% or less of a card's limit. -- from 7 Ways to Fix Your Credit Score In other words, ALWAYS pay off your balance if you can. But don't fill up your card to the max of your credit limit each month. i.e. if your credit limit is $5000, only spend $2000 each month. MrChrister's answer is just plain wrong. Your history of carrying debt or paying interest has nothing to do with your credit score. The biggest factors are payment history, debt to available credit ratio and length of credit history. If you have active credit accounts for 5 years, have 10-15k in limits on credit cards and put gas and groceries on a credit card that is paid in full each month, you'll have a top notch credit rating. There is no way to tell from a credit report whether you carry a balance for pay in full. Anyone who gets into debt to improve a credit score is ignorant of the process. If you have bad credit, here's how you improve it: If you want to stay in the sub 30% range to avoid 'high utilization' on your card, make sure your credit is > 3.33x your usage.  For your numbers, a 2500 limit would probably keep you out of 'high utilization'. The primary reason to do this is to stay off your lender's 'high risk' list.  Due to the risk perceived by CCC's, accounts with greater than 30% utilization are reported as high utilization. Keep in mind that utilization does not have a history.  So you can drop your utilization a couple of billing cycles before you apply for a high cost item (e.g. car or house) and your score should bump up a bit. "Forecasts of stock market direction are not reliable, so you shouldn't be putting much weight on them.  Long term, you can expect to do better in stocks, but obtaining this better expected return has the danger of ""buying in"" to the market at a particularly bad moment, leading to a substantially lower return.  So mitigate that risk while moving in a big piece of cash by ""dollar cost averaging"".  An example would be to divide your cash hoard (conceptually) into say six pieces, and invest each piece in the index fund two months apart.  After a year you will have invested the whole sum at about the average of the index for the year."