Weight loss time calculator
Use the Weight Loss Time Calculator with current and goal weights, weekly rate, and start date to estimate time to goal, projected date, and a buffered plan to download.
Estimate how long it will take to lose weight
Planning interval with 10%–20% buffer
Wait for valid input
The results will be displayed after the input is valid.
- Need to change weight
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- linear time required
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- linear estimate date
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- Weekly weight ratio
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This tip is used to identify obviously faster input and is not a medical judgment.
weight loss plan
| Weekly | Check date | Planned weight | Cumulative weight loss | Actual weight | Remarks |
|---|---|---|---|---|---|
| After entering a valid weight loss goal, the planned weight and review date will be generated on a weekly basis. | |||||
The schedule is for stage review and does not mean that your weekly weight must accurately reach the values in the table.
How to use the weight loss time calculator
- Enter weightFill in your current weight and target weight, and select kilograms or pounds.
- Set speed and dateFill in the expected weekly rate of change and select a planned start date.
- View and reviewView linear dates, buffer intervals and speed tips; when losing weight, you can download the schedule and review it regularly based on actual trends.
Limitations and Healthy Boundaries
- The model assumes a constant weekly rate of change and that actual body weight does not change linearly over time.
- Results are not a guaranteed date and plateaus, moisture fluctuations, illness, travel and performance interruptions may alter the cycle.
- Pregnant women, minors, people at risk for eating disorders, and people with chronic diseases or medications that affect their weight should not make their own plans based on this.
Learn more
Calculation formulas and assumptions
Week numberNumber of weeks = |Current weight − Target weight| ÷ Weekly change rate
Linear projected dateLinear projected date = start date + ceil (number of weeks × 7) days
Planning intervalPlanning interval = linear period × 110% to 120%
Kilograms are used internally for calculation; switching to pounds only changes the input and display units. Dates are rounded up to the whole day.
Checking examples with results
Linear results: 20 weeksWith a current weight of 80 kg, a target weight of 70 kg, and a weekly change of 0.5 kg, a change of 10 kg is required. 10 ÷ 0.5 = 20, a total of 140 days.
Planning horizon: 22–24 weeksAdd a 10%–20% planning buffer to the 20-week baseline.
Privacy, local processing and tools information
All calculations and PDF generation happen locally in the browser. No weight or date data is uploaded.
The tool only uses localStorage to save kg/lb unit preferences, not weight, speed or date.
The shared link will include entered weight, weekly pace, and start date; if this data is private, please do not post the link publicly.
Copy results and copy sharing links only access the clipboard after the user actively clicks on them; a downgrade prompt will be displayed when the browser denies permission.
The PDF is only generated and downloaded locally in the browser after the user clicks it, and the temporary Object URL will be revoked after downloading.
Methods and Health Information Sources
- Centers for Disease Control and Prevention (CDC): Gradual Weight LossUsed to illustrate common progressive weight loss rhythms.CDC: Instructions for Gradual Weight Loss
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): Weight PlanningUsed to illustrate that weight change is not a simple long-term linear process.NIDDK: Weight Planning Tool
- National Institute of Mental Health (NIMH): Eating DisordersUsed to illustrate eating disorder risk boundaries.NIMH: Eating Disorder Information
This tool does not copy third-party code, icons, images, or data files; external links are only used to support the methods and healthy boundary descriptions in the page.
FAQ
Why are the results not guaranteed dates?
Actual weight is affected by water, diet, exercise, sleep, medications, hormones and health conditions. The fixed speed can only be used as a planning baseline.
Can both weight loss and weight gain be calculated?
Yes. The tool automatically determines direction, but does not judge whether the target is suitable, nor does it provide diet or training prescriptions.
Do speed tips mean safety?
Doesn't mean. It only identifies significantly faster input and is not a substitute for evaluation by a physician or registered dietitian.
Why add 10%–20% buffer?
Buffers can accommodate plateaus, short-term fluctuations and planned disruptions, making “guaranteed dates” less misleading.