You can check with a local Realtor. They have access to comparable sales and can give you a pretty good idea what homes are worth in your area.The only way to find out the exact market value of your home is to hire a professional appraiser to come in and do the job.
There are many different online value estimators that are free, another source is a program made available through the government that generates the house value based on historical appreciation rates in your area.
Some online value estimators are actually lead generation sites for realtors. keep that in mind when using them.
To get a general idea of your home's value you can use an online value estimator. Online value estimators can provide you with a general idea as to the value of your home on paper. These should not be construed as an appraisal report or a true value of your home, but can usually provide a basic idea of your home's value.
If you are unsure of the value and it is crucial that you need find out an accurate amount, hiring a professional appraiser is possible as well. This can be the most expensive option, but also the most accurate.