Enter your numbers. Get a science-backed, day-by-day weight cut plan built for IBJJF same-day weigh-in rules. Every recommendation is grounded in sports science.
Used to calculate your post-weigh-in rehydration window. Defaults to morning (conservative).
Used for TDEE (Mifflin-St Jeor). Most BJJ competitors training + rolling 5 days/week = Active.
Weigh yourself first thing in the morning, after using the restroom, naked or consistent minimal clothing.
The class limit includes your gi. Your naked body must be under: class limit minus gi weight.
Typical weights — Competition lightweight gi: 2.6–3.3 lbs (1.2–1.5 kg) · Standard gi: 4.0–5.5 lbs (1.8–2.5 kg)
Weigh your gi dry before competition week. A damp gi has cost athletes their weight class.
For educational purposes only · Not medical advice · Individual results vary · Consult a physician before any significant weight cut · Adults 18+ · Use at your own risk
Educational use only — not medical advice. This plan is a science-based estimate, not a guarantee. Individual results vary based on factors this tool can't assess (medications, metabolic conditions, cardiovascular health, eating disorder history, pregnancy). Using this tool doesn't create a medical or coaching relationship. Consult a physician before any significant weight cut. If you experience chest pain, heart palpitations, inability to urinate, or confusion — stop and seek medical attention immediately. Adults 18+ only. Use at your own risk; creators disclaim all liability for outcomes.
Honey is ~38–40% fructose and 31–38% glucose (fructose-dominant for most varieties; acacia honey is especially high in fructose, while some polyfloral honeys approach 50/50). The two sugars are absorbed via separate intestinal transporters (GLUT5 for fructose, SGLT1 for glucose), which helps total absorption speed — but fructose is routed primarily to liver glycogen, not muscle glycogen. For muscle glycogen replenishment after weigh-in, glucose-dominant sources are more effective: white rice, potatoes, sports drink with glucose/maltodextrin.
Where honey genuinely earns its place: it's enzymatically pre-digested, extremely gentle on a depleted GI tract, portable, stable in a gear bag, and replenishing liver glycogen helps restore blood glucose stability quickly. 1–2 tablespoons (~21–42 g) alongside your ORS in the first 30 minutes is smart — just pair it with rice or a glucose-based sports drink for the muscle glycogen side.
Cutting more than 3% of body weight same-day is considered high risk by sports science consensus. This tool does not account for medications, metabolic disorders, eating disorder history, cardiovascular disease, kidney disease, or pregnancy. If any of these apply, do not use this tool without physician supervision.
This tool does not recommend diuretics, IV rehydration, or any supplementation outside of standard electrolytes.
All weight targets, calorie recommendations, and timelines are model-based estimates. Individual physiological variation means actual results will differ. The tool makes no guarantee that following this plan will result in making weight, improved performance, or any specific health outcome.
By using this tool, you confirm you are 18 or older, have read and understood the medical disclaimer above, and accept sole responsibility for any decisions you make based on this information. This tool is provided "as is" without any warranty, express or implied.
Source citations: Garthe et al. (2011) weight loss rate and lean mass; Reale et al. (2018) water loading in combat sports; Barley et al. (2018) weight making in combat sports; Brito et al. (2012) prevalence of dehydration before competition; Casa et al. (2000) NATA position statement on hydration.