📖 Overview
Use this tool to set a realistic timeline for weight-change targets.
🧪 Example Scenarios
Use these default and higher-pressure example inputs to explore how sensitive this calculator is before using your real numbers.
| Input | Base Case | Higher Pressure Case |
|---|---|---|
| Current Weight (kg) | 92 | 105.8 |
| Target Weight (kg) | 82 | 94.3 |
| Weekly Weight Change (kg) | 0.5 | 0.58 |
⚙️ How It Works
This estimates weeks needed to reach a target weight using a consistent weekly change rate.
The Formula
Weeks = |Current Weight − Target Weight| ÷ Weekly Rate
| Current Weight | Starting body weight in kg or lbs |
| Target Weight | Goal body weight in kg or lbs |
| Weekly Rate | Expected change per week (0.25–1 kg is typically sustainable) |
💡This calculator is scenario-based. Better input quality leads to better decision quality.
⚠️Rates above 1 kg/week for weight loss are generally considered aggressive and can be counterproductive — they may lead to muscle loss and metabolic adaptation. Consult a healthcare professional for personalized advice.
Quick Reference
| Weight Gap | 0.25 kg/wk | 0.5 kg/wk | 0.75 kg/wk | 1 kg/wk |
|---|---|---|---|---|
| 5 kg | 20 weeks | 10 weeks | 7 weeks | 5 weeks |
| 10 kg | 40 weeks | 20 weeks | 14 weeks | 10 weeks |
| 15 kg | 60 weeks | 30 weeks | 20 weeks | 15 weeks |
| 20 kg | 80 weeks | 40 weeks | 27 weeks | 20 weeks |
When To Use This
- Use this tool when you need a fast decision during active planning or execution.
- Use this before committing money, time, or tradeoffs that are hard to reverse.
- Use this to compare options using the same assumptions across scenarios.
Edge Cases To Watch
- Results can be misleading if key inputs are missing, stale, or unrealistic.
- Very small or very large values may amplify rounding effects and interpretation risk.
- If assumptions change mid-decision, recalculate before acting.
Practical Tips
💡 Use sustainable weekly rates.
💡 Recalculate periodically using updated body weight.
💡 Run a best-case, base-case, and worst-case scenario before deciding.
💡 Use recent real values, not ideal assumptions, for better accuracy.
Frequently Asked Questions
❓ Is progress always linear?
No, real-world progress can vary due to adaptation and adherence.
❓ Can this handle weight gain goals?
Yes, it supports both gain and loss timelines.