Reps em Reserva (RIR)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The Repetitions in Reserve (RIR) Calculator is a useful tool for those who practice weightlifting. It helps determine the number of repetitions you can perform with a given weight, considering your strength reserve. RIR is calculated based on the formula: RIR = (Maximum number of repetitions - Number of repetitions performed) / Maximum number of repetitions. This allows you to adjust your training according to your goals and fitness level.
RIR is commonly used by athletes and weightlifters to monitor progress and avoid injuries. When you are training with a high RIR, you are working close to your limit, which can be beneficial for strength gains, but also increases the risk of injury. A low RIR indicates that you are working with a lower intensity, which may be more suitable for recovery or for beginners.
Using the Repetitions in Reserve Calculator, you can enter the maximum number of repetitions you can perform with a given weight and the number of repetitions you performed in the exercise. The calculator then provides the RIR value, allowing you to adjust your training safely and effectively.
It's essential to remember that RIR is just one of the tools available to plan and monitor your training. Other factors, such as training volume, frequency, and weight progression, are also important for success in strength training.
Frequently asked questions
What is RIR and why is it important?
RIR stands for Repetitions in Reserve and is a measure that indicates how close you are to your strength limit in an exercise. It's important because it helps adjust the intensity of your workout and avoid injuries.
How does the Repetitions in Reserve Calculator work?
The calculator uses the formula RIR = (Maximum number of repetitions - Number of repetitions performed) / Maximum number of repetitions to provide the RIR value.
What is the ideal RIR for my workout?
The ideal RIR depends on your goals and fitness level. A high RIR is more intense and suitable for strength gains, while a low RIR is less intense and may be more suitable for recovery or beginners.
Can I use RIR for any type of exercise?
RIR is commonly used for strength exercises, such as weightlifting. However, it can be adapted for other types of exercises that involve a variable workload.
How can I apply RIR to my daily workout?
You can use RIR to adjust the weight and number of repetitions in your exercises, ensuring that you are training with the right intensity for your goals.