Ever wondered how to find weight without weight machine? It’s a common situation, whether you’re traveling, at home without equipment, or just curious. You don’t need a digital scale to get a good estimate of your body weight. Several simple alternative methods can give you a useful number.
These techniques use common objects and basic math. They are surprisingly effective when you need a quick check. Let’s look at the best ways to do this.
How To Find Weight Without Weight Machine
This primary method uses a known weight and the principle of a simple lever. You’ll need a long, sturdy board (like a 2×4), a cylindrical fulcrum (a pipe, rolling pin, or similar), and an object with a known weight.
A standard 10-pound bag of flour or rice works perfectly. Or you can use a dumbbell if you have one. The key is knowing the exact weight of your reference object.
Setting Up Your Homemade Scale
First, find a flat, hard surface. Place your fulcrum in the middle of the area. Then, balance the long board across it. This board is your lever.
Make sure it balances evenly when nothing is on it. You may need to adjust the board’s position slightly. It needs to be level.
Step-by-Step Balancing Process
- Place your known weight (e.g., the 10-pound bag) on one end of the board.
- Slowly move the board so the known weight’s end is on the ground and the other end is up in the air.
- Now, you (the unknown weight) carefully get on the high end of the board.
- Gradually slide the board back and forth over the fulcrum until both ends are balanced and level.
Once balanced, measure the distance from the fulcrum to the known weight. Then, measure the distance from the fulcrum to where you are sitting. The formula is simple.
The Seesaw Formula
Your weight is calculated using this ratio: (Distance to Known Weight / Distance to You) x Known Weight.
For example: If the known weight is 10 pounds and it’s 4 feet from the fulcrum, and you are 2 feet from the fulcrum, your weight = (4 / 2) x 10 = 20 pounds. That’s obviously not right for an adult, so let’s use a realistic example.
If you are 3 feet from the fulcrum and the 10-pound weight is 1.5 feet from the fulcrum on the other side: (1.5 / 3) x 10 = 5 pounds. That’s not correct either—this shows you need to ensure the board is balanced correctly. The distances must be measured precisely from the center of the fulcrum.
Let’s say the 10lb weight is 2 feet from the fulcrum, and you are 1 foot from the fulcrum when balanced. Your weight = (2 / 1) x 10 = 20 pounds. That’s still off. Actually, the correct formula is: Your Weight = (Distance to Known Weight / Distance to You) * Known Weight. So if the known weight is farther from the fulcrum than you are, you weigh more. If it’s closer, you weigh less.
Using a Bathroom Scale and a Plank
If you have access to a bathroom scale but it has a low maximum, this trick works. Find a rigid plank or board long enough to span two scales. Place one scale on either side of the board, then stand in the middle.
Add the two weights shown on the scales together. That’s your total body weight. This method distributes your weight so you don’t overload one scale.
Estimation Using Body Measurements
For a less hands-on method, body measurements can provide a rough estimate. This is common in medical and fitness settings when a scale isn’t available. Accuracy depends on precise measuring.
Navy Body Fat Formula
The U.S. Navy has a method to estimate body fat, which can then be used to estimate weight when combined with height. You’ll need a flexible measuring tape.
- Measure your height in inches.
- Measure your neck circumference at its narrowest point.
- Measure your waist at the navel for men, or at the narrowest point for women.
- Measure your hips at the widest point for women (men typically don’t need hip).
Plug these numbers into an online Navy body fat calculator. Once you have an estimated body fat percentage, you can use online calculators that derive weight from body fat, height, and sex. It’s an indirect method, but it can give a ballpark figure.
BMI Chart Back-Calculation
This is a very simple estimation tool. First, you need to honestly assess your body type. Look at a standard Body Mass Index chart online.
Find your height on the chart. Then, look at the weight ranges for categories like “Normal,” “Overweight,” etc. Based on your self-assessment, you can pick a mid-range weight for your perceived category.
For example, if you are 5’9″ and you believe you are in the “Normal” range (126-169 lbs), you might estimate 150 lbs. This is highly subjective but can be a starting point.
Everyday Object Comparisons
This method is less about a number and more about tracking changes. You use a common household item that you know the weight of as a reference.
The Water Jug Method
A standard gallon of water weighs 8.34 pounds. Lift a one-gallon jug in each hand. That’s about 16.7 pounds total.
Now, think about your last weigh-in. If you previously lifted two 10-pound dumbbells (20 lbs) and it felt similar to the water jugs, you might have lost a few pounds. This is for relative comparison, not an exact measure.
Using Grocery Items
Next time you’re at the store, pick up items with clear weights. A 5-pound bag of sugar, a 10-pound bag of potatoes, a 20-pound bag of dog food.
Get a feel for these weights. Mentally compare how heavy you feel relative to these known objects. It’s not precise, but it builds awareness. If you can easily lift a 40-pound bag of soil, you have a sense of what 40 pounds feels like on your body.
Water Displacement Method (Archimedes’ Principle)
This is a science-lab method, but it can be done at home with a large container. It measures volume, which you then convert to weight using an estimated body density.
You need a bathtub, a large container that you can fit into, and a way to measure water volume. Fill the tub to the very brim. Then, slowly and carefully get into the tub, letting the water overflow into your collection container.
Measure the volume of the overflowed water in gallons. Convert gallons to liters (1 gallon = 3.785 liters). The weight of the displaced water in kilograms is roughly equal to your body volume in liters.
To get your mass in kilograms, you multiply your volume by average body density (about 1.05 kg/L for men, 1.04 kg/L for women). Then convert kg to pounds. This method is messy and complex, but it’s theoretically accurate.
Tracking Progress Without a Scale
Sometimes, the number matters less than overall progress. Here are non-scale ways to track your fitness journey.
- Tape Measure: Track inches lost on your waist, hips, chest, and thighs.
- Clothing Fit: How your favorite jeans or belt fits is a great real-world indicator.
- Progress Photos: Take front, side, and back photos every few weeks in consistent lighting.
- Strength and Endurance: Can you do more push-ups, run farther, or lift heavier groceries? That’s progress.
- Energy Levels: General feelings of well-being and vitality are key metrics.
These methods often tell you more about your health than the scale alone. They show body composition changes that weight can’t reveal.
Frequently Asked Questions (FAQ)
Can I use a regular tape measure to estimate weight?
Yes, but indirectly. By taking neck and waist measurements (and hip for women), you can use the Navy formula or other online calculators to get an estimated weight. It’s not perfect, but it provides a useful estimate.
What is the most accurate homemade method?
The seesaw or lever method with a known weight and precise measurements is likely the most accurate DIY approach. It’s based on solid physics principles, assuming you execute it carefully and your fulcrum is stable.
How can I check if I’ve gained or lost weight without a machine?
Use the clothing fit test or a tape measure. These are the simplest and most reliable indicators of body change. A belt notch or a pair of pants that feels looser is a clear sign of weight loss, regardless of the number.
Are smartphone apps that estimate weight accurate?
Apps that use photos or basic inputs are generally not accurate for weight. They can be fun, but don’t rely on them. Apps that use measurement inputs (like the Navy formula) are only as accurate as your measuring skill.
Why might my estimated weight be different from the scale?
All alternative methods have margin for error. The lever might not be perfectly balanced, measurements can be off, or body density estimates may not match your actual composition. They give a close approximation, not an exact figure.
Remember, the goal is often to track trends, not to know an exact number to the decimal. Using these methods consistently can show you if you’re moving in the right direction. They empower you to understand your body better, even when traditional tools aren’t around.