Relative Fat Mass (RFM) Calculator by Solve My Day: The Smartest Way to Measure Body Fat

When it comes to tracking fitness and health, most people rely on weight or Body Mass Index (BMI). But here’s the truth: neither gives you the full picture. Weight fluctuates daily due to water retention, and BMI can misclassify muscular individuals as overweight.

That’s where Relative Fat Mass (RFM) steps in. It’s a scientifically proven, more accurate way to measure body fat—without expensive scans or complex calculations.

And now, Solve My Day has made it even easier with their RFM Calculator. This tool lets you determine your body fat percentage quickly using just your height and waist circumference.

In this guide, we’ll cover:

1. What RFM is and why it’s better than BMI
2. How the RFM Calculator works
3. How to measure yourself for the best accuracy
4. What your results mean
5. How to use your RFM score to improve your health

What Is Relative Fat Mass (RFM)?

RFM is a simple yet powerful equation designed to estimate body fat percentage. Unlike BMI, which only considers height and weight, RFM uses your waist size—one of the best indicators of body fat and overall health risks.

Why RFM is Better Than BMI

BMI has been the standard for decades, but it has serious flaws:

✅ It doesn’t differentiate between muscle and fat. A muscular person and an overweight individual can have the same BMI.

✅ It ignores fat distribution. Belly fat (visceral fat) is far more dangerous than fat stored elsewhere, but BMI doesn’t account for this.

✅ It’s outdated. BMI was created in the 1830s—before modern health science.

In contrast, RFM is scientifically backed and developed in 2018 by researchers at Cedars-Sinai Medical Center. It directly correlates with body fat percentage, making it more accurate and relevant.

How the RFM Calculator by Solve My Day Works

The RFM formula is:

• For men: RFM = 64 – (20 × height/waist circumference)
• For women: RFM = 76 – (20 × height/waist circumference)

Unlike BMI, you don’t need to know your weight. Just two easy measurements—height and waist—can tell you whether your body fat percentage is in a healthy range.

Why Use the Solve My Day RFM Calculator?

✅ Easy to use – No complex math. Just enter your height and waist size.

✅ Instant results – Get your body fat percentage in seconds.

✅ More accurate than BMI – Focuses on fat distribution, not just weight.

✅ Great for tracking progress – See real changes in body composition over time.

How to Measure Yourself Correctly for Accurate RFM Results

To get the most precise results from the RFM Calculator, you need to measure yourself correctly. Here’s how:

Step 1: Measure Your Height

1. Stand straight against a wall, barefoot.
2. Use a measuring tape or a height chart.
3. Make sure your heels, back, and head are touching the wall.
4. Mark the top of your head and record the measurement in centimeters or inches.

Step 2: Measure Your Waist

1. Stand relaxed—don’t suck in your stomach.
2. Wrap a flexible measuring tape around your waist at navel level.
3. Keep the tape parallel to the floor and snug, but not tight.
4. Breathe normally and take the measurement.

🔹 Pro Tip: Measure in the morning before eating for consistent results.

Understanding Your RFM Score

Once you enter your height and waist size into the RFM Calculator, you’ll get your body fat percentage. But what does that number mean?

Here’s a general guide:

• For Men:

1. Essential Fat: 2–5%
2. Athletes: 6–13%
3. Fit: 14–17%
4. Average: 18–24%
5. Overweight: 25% or more

• For Women:

1. Essential Fat: 10–13%
2. Athletes: 14–20%
3. Fit: 21–24%
4. Average: 25–31%
5. Overweight: 32% or more

🔹 If your RFM is too high, you may be at risk for heart disease, diabetes, and metabolic disorders. Reducing excess fat through a healthy diet and exercise can improve your overall health.

🔹 If your RFM is too low, it might indicate muscle loss, nutritional deficiencies, or hormonal imbalances.

How to Use Your RFM Score to Improve Your Health

1. Set Realistic Goals

If your RFM is higher than the recommended range, aim for a gradual reduction of 1–2% body fat per month. Crash dieting isn’t sustainable—focus on small, long-term changes.

2. Adjust Your Diet

• Eat more protein to build muscle and burn fat.
• Cut processed foods, sugars, and refined carbs.
• Increase fiber intake to feel fuller for longer.
• Stay hydrated. Sometimes, thirst is mistaken for hunger.

3. Strength Training is Key

Muscle burns more calories than fat—even at rest. Incorporate:

✔ Weightlifting (3–4 times per week)

✔ Bodyweight exercises (push-ups, squats, lunges)

✔ Resistance bands or machines

4. Increase Cardio

Cardio helps burn fat, but the right type matters:

• HIIT (High-Intensity Interval Training): Burns fat quickly
• Steady-state cardio: Running, cycling, or brisk walking for 30–45 minutes.

5. Track Your Progress

Measure your RFM every 2–4 weeks to see changes. Combine this with progress photos and waist measurements to get a complete picture of your transformation.

Common Questions About the RFM Calculator

1. Is RFM more accurate than BMI?

Yes! BMI only considers weight and height, while RFM factors in waist circumference, making it a better predictor of health risks.

2. Can I use RFM if I’m an athlete?

Absolutely! Unlike BMI, which often misclassifies athletes as overweight, RFM gives a more accurate representation of body fat.

3. How often should I check my RFM?

Once a month is ideal. Daily fluctuations don’t matter—long-term trends do.

4. What if my RFM is too high?

Start making small changes to your diet and exercise. Even a 5% reduction in body fat can dramatically improve health.

5. Can I reduce body fat without losing weight?

Yes! Strength training + a clean diet can increase muscle while burning fat. The scale might not move, but your body composition will improve.

Final Thoughts: Why You Should Try the RFM Calculator Today

Tracking body fat is more important than tracking weight. Solve My Day’s RFM Calculator gives you a clear, science-backed way to measure fat percentage—without the flaws of BMI.

✅ Fast and easy – No need for special equipment

✅ More reliable than BMI – Focuses on fat distribution

✅ Perfect for tracking progress – See real body composition changes

Take Control of Your Health Today!

Want to know your true body fat percentage? Head over to Solve My Day’s RFM Calculator and get your results in seconds.

Small steps today = Big health wins tomorrow. Start tracking, stay consistent, and watch your body transform!