Your credit score is something every smart consumer should know, but with so many credit scoring models to choose from, it's hard to decide which to use. To help you make sense of the credit-scoring industry, we spoke with four major trackers to find out what sets them apart. Some models, like FICO, include anything and everything that appears on a consumer's report and issue scores based on their own models, others like CreditKarma and Credit Sesame turn to the three bureaus, Equifax, Experian and TransUnion to generate scores.

Keep reading to see how they differ:

FICO

One of the more notable scoring models out there, FICO assesses five areas to determine credit risk: current debt, payment history, types of credit used, new credit and length of credit history.

Score range: 300-850

Why it's different: Years of research went into developing FICO's model, which determines a users' risk solely based on credit data, says Anthony Sprauve, the company's director of public relations. It's the one lenders turn to the most, and the one that includes information such as how many times you've been turned down for a card or whether an account's been sent to collections. What it doesn't include is your race, salary/income or other demographic data, like marital status.

How it's calculated: In addition to the five areas outlined above, "the FICO Score considers both positive and negative information in a person's credit report," says Sprauve. "Late payments will lower someone's FICO score, but establishing or re-establishing a good track record of making payments on time will raise their score." It's just another way for the company to determine if you'll repay a debt.

Assessment time frame: According to Sprauve, FICO accounts for the following: at least one account that's been open for six months or more, at least one undisputed account that's been reported to the credit bureau within the past six months, and whether the person on the report is deceased.

What it costs: You can access your FICO score for a one-time fee of $19.95. "The price also includes a credit report from TransUnion or Equifax," adds Sprauve.

CreditKarma

With its colorful site and accessible voice, CreditKarma is clearly for cool kids who care about credit. The well-received site also boasts a comprehensive scoring model that even non-geeks can comprehend.

Score range: 300-850

Why it's different: Two of CreditKarma scores are calculated by TransUnion. CreditKarma also provides users with a VantageScore "to try to create a more universal and accurate scoring system," says Amy Leone, the company's public relations coordinator.

How it's calculated: Since CreditKarma's scores are derived from TransUnion, which calculates its scores according to terms agreed upon by all credit bureaus, consumer behaviors, such as how many times you've applied for a credit card or how much debt you're carrying in relation to your credit limit (credit card utilization), are factored in.

Assessment time frame: "Credit scores attempt to analyze your entire credit history to give lenders an idea of whether or not it's a good risk to extend credit to you," says Leone. However, derogatory items fall off after seven years (unless you dispute them before then), while newer items are sometimes weighted more heavily than older ones on a report.

What it costs: Signing up to receive the score is free, and members can opt to receive a Credit Report Card, which offers other resources and sends notifications if your score changes.

Credit Sesame

Credit Sesame first made headlines in 2011 with its credit badge, a social media marker of excellent credit. Now the company's moved into the credit scoring market, with a score that is similar to FICO's.

Score range: 360-840

Why it's different: "Credit Sesame uses Experian's National Equivalency Score, which is designed to mimic a consumer's FICO score," says Linden Garcia, a company spokesperson.

How it's calculated: Here's how Credit Sesame's model breaks down: length of credit history (15%), payment history (35%), debt owed (30%), whether the customer's applied for new credit (10%), the mix of credit, including retail accounts, installment loans, car and mortgage loans (10%).

Assessment time frame: Since Credit Sesame relies on Experian's scoring model, it's similar to FICO and CreditKarma's models in that negative items come off after seven years and recent activity is monitored more closely.

What it costs: Credit Sesame users can access their score for free, in addition to other features such as "peer comparison data" and credit monitoring.

VantageScore

One of the better-known models of the bunch, VantageScore has a lot in common with FICO, to the point where some consumers mix them up.

Score range: 501-990

Why it's different: Unlike FICO, VantageScore relies on six rather than five areas to determine its scores, which include: payment history, utilization, balances, depth of credit, available credit and recent credit.

How it's calculated: Here's how the scores are weighted: payment history (32 percent), utilization (23 percent), balances (15 percent), depth of credit (13 percent) and recent credit (10 percent), and available credit (7 percent).

Assessment time frame: Similar to the other scoring models, negative information will come off after seven years, and recent activity is heavily considered.

What it costs: VantageScore itself does not market its scores. Experian's site advertises the ability to view your VantageScore for $7.95.