Rental Security Deposit Calculator

Note that this interest rate calculation only applies to interest accruing on a security deposit under a residential lease or mobile home park rental agreement on or after January 1, 2015.

As of January 1, 2015, for all Maryland jurisdictions, the amount of interest a landl​ord or mobile home park ​owner must pay residential tenant upon return of the security deposit is the greater of the daily U.S. Treasury yield curve rate (“Constant Maturity Treasury”) for one year, as of the first business day of each year, or 1.5%.

We provide this customized calculator that determines the interest due on a security deposit by allowing a user to enter a start date (the date on which the security deposit was given to the landlord), a tenancy end date, the county in which the residence is located, and the amount of the security deposit. 

Interest is only payable on security deposits of $50 or more, and accrues at monthly intervals from the beginning of the tenancy. No interest is due or payable unless the landlord has held the security deposit for at least 6 months, or for any period less than a full month (which may happen at the end of a lease).

For information on the 2014 Maryland legislation that required the creation of this calculator, and the methodology of its calculations, go to Background & Methodology.

For more information on Maryland landlord/tenant laws and support available to resolve disputes, please refer to the Maryland Attorney General's Office, Consumer Protection Division

Also available is the downloadable ebook - Landlords and Tenants: Tips on Avoiding Disputes​, which provides valuable information on state law that these arrangements are subject to.​​​​​​​​​​​​

Contact Information

Please email the webmaster at dhcd.webmaster@maryland.gov​ if you are facing issues with the Calculator.