Average Salary: $45,740
Expected Lifetime Earnings: $1,910,000
Private detectives make a median annual wage of between $40,000-$50,000 (source). The average rate for a private detective is $50 an hour but the really good ones in Hollywood make ten times that figure. Planting evidence costs extra (note: please do not plant any evidence, anywhere).
To calculate a quote for a case, a private detective will estimate how many hours they need to work. Once they figure out the hours, they give the client a quote before investigating. The client must review cases that run longer than the amount estimated for the investigation. It's sorta like working with a contractor to build a guest house. There's the rate they quote; then there’s the real rate which you actually pay (which is almost always higher).
If you go into business for yourself, live in a city, or are highly experienced, you can charge more. You need lots of dark human interaction to really make dough…ten million stories in the big city and all that…. Most private detectives start out in an entry-level position at a firm. Oftentimes, insurance companies and other business will hire a firm to conduct background checks or investigate questionable claims.
Also, private investigating firms typically pay their employees on an hourly basis. This isn’t a 9-5 kind of a job, though many days it'll be 9pm to 5am. You may need to follow someone in the middle of the night or put in 12 hours a day investigating financial fraud for a major client. You can make more money if you take on what is considered to be high-risk cases. Example: investigating hazardous waste. You might even find yourself fighting teenage mutant turtles if you go this route.
Big money being investigated can hire its own big money anti-private-detective people too. How many Jason Bournes are out there on Craigslist looking for a gig?
In fact, only 21 percent of all private detectives are self-employed. Self-employed private detectives figure out their rates by looking at the competition and factoring in their experience. They also have to factor in all the personal expenses that come with being self-employed. No one else is going to pay for that stapler.
Generally, it is best to meet clients in an office rather than a back alley. You must also get a business license (source). Keeping up on the paperwork is pretty mundane stuff. It's not all car chases and fake moustaches when it comes to being a private detective.