Rate or rates may be:

• Rate (mathematics), a specific kind of ratio, in which two measurements are related to each other
• Rate of travel, or velocity
• Naval rating or rate, terms used to designate specialty or seniority of enlisted naval personnel.
• Rate of a ship, a term for a sail ship's firepower in the British Royal Navy
• Bit rate, number of bits that are processed per unit of time
• Rates, a Portuguese parish and town located in the municipality of Póvoa de Varzim
• Rates (tax) a type of property tax in the United Kingdom

In science and finance

• Rate function, a function used to put a number to the probabilities of a rare event
• Rates (tax), a type of taxation system used to fund local government
• Reaction rate in Chemistry
• Exchange rate, how much one currency is worth in terms of the other

In human growth

• Birth rate, the childbirths per 1,000 people per year
• Mortality rate, a measure of the number of deaths in some population

As an initialism

• Radioisotopes and the Age of the Earth, a project of creation geophysics