{"id":31079,"date":"2026-10-23T10:24:52","date_gmt":"2026-10-23T10:24:52","guid":{"rendered":"https:\/\/kriyasya.com\/pulse\/one-rep-max-calculator-1rm-brzycki-epley-strength-formulas\/"},"modified":"2026-10-23T10:24:52","modified_gmt":"2026-10-23T10:24:52","slug":"one-rep-max-calculator-1rm-brzycki-epley-strength-formulas","status":"publish","type":"post","link":"https:\/\/kriyasya.com\/pulse\/one-rep-max-calculator-1rm-brzycki-epley-strength-formulas\/","title":{"rendered":"One-Rep Max Calculator: 1RM Strength Formulas, Brzycki vs Epley &#038; Percentage Charts"},"content":{"rendered":"<p>Your <strong>One-Repetition Maximum (1RM)<\/strong> is the absolute pinnacle benchmark of neuromuscular strength: the maximum load in kilograms or pounds that you can lift for a single, complete repetition with sound biomechanical form. Knowing your 1RM is essential for designing periodized strength training programs, calculating submaximal working percentages (e.g., 5 sets of 5 at 80% 1RM), and benchmarking athletic performance. However, attempting a true, maximal 1RM lift under a heavy barbell carries substantial risks of acute joint injury, tendon strain, or central nervous system exhaustion. The <strong>One-Rep Max Calculator<\/strong> utilizes submaximal repetition formulas (Brzycki, Epley, Lander) to accurately predict your true 1RM without risking physical injury.<\/p>\n<aside class=\"kr-world-bridge kr-world-bridge--fitness\" data-kriyasya-world=\"fitness\" style=\"margin:40px 0;padding:30px 34px !important;background:radial-gradient(circle at 90% 15%, rgba(16,185,129,0.12), transparent 30%), radial-gradient(circle at 10% 88%, rgba(5,150,105,0.10), transparent 30%), linear-gradient(135deg, #f4fbf8 0%, #ffffff 55%, #e8f7f0 100%) !important;border:1px solid rgba(16,185,129,0.24) !important;border-radius:20px !important;box-shadow:0 10px 32px rgba(16,185,129,0.06) !important;position:relative;overflow:hidden;\">\n<div class=\"kr-world-bridge__copy\" style=\"margin-bottom:18px;\">\n<p class=\"kr-eyebrow\" style=\"display:inline-flex;align-items:center;padding:5px 14px;background:rgba(16,185,129,0.12);color:#059669;border-radius:999px;font-size:0.75rem;font-weight:700;text-transform:uppercase;letter-spacing:0.08em;margin:0 0 12px 0;\">Neuromuscular Strength Lab<\/p>\n<h3 class=\"kr-world-bridge__title\" style=\"margin:0 0 8px 0;color:#06251b !important;font-family:'Playfair Display',Georgia,serif;font-size:1.55rem;font-weight:700;line-height:1.3;\">One-Rep Max (1RM) Strength Calculator<\/h3>\n<p class=\"kr-world-bridge__description\" style=\"margin:0;color:#274b40 !important;font-size:1.02rem;line-height:1.65;\">Calculate your maximum single-rep strength across bench press, squat, and deadlift using validated submaximal formulas (Brzycki, Epley).<\/p>\n<\/p><\/div>\n<p>  <a class=\"kr-button kr-button--primary\" href=\"https:\/\/kriyasya.com\/fitness\/one-rep-max-calculator.php\" target=\"_blank\" rel=\"dofollow\" style=\"display:inline-flex;align-items:center;gap:8px;padding:13px 30px;background:linear-gradient(135deg,#10b981 0%,#059669 100%) !important;color:#ffffff !important;font-size:0.96rem;font-weight:600;border-radius:999px;text-decoration:none;box-shadow:0 4px 16px rgba(16,185,129,0.25);transition:all 0.2s ease;\"><br \/>\n    <span>Calculate Your 1RM<\/span><span style=\"font-size:1.15rem;line-height:1;\">&rarr;<\/span><br \/>\n  <\/a><br \/>\n<\/aside>\n<h2>The Classical Predictive Strength Equations<\/h2>\n<p>Sports science has validated multiple mathematical formulas that convert submaximal repetitions performed to failure (typically between 2 and 10 reps) into predicted 1RM values:<\/p>\n<ul>\n<li><strong>Brzycki Formula (1993):<\/strong><br \/>\n  <code>1RM = Weight &divide; (1.0278 - (0.0278 &times; Repetitions))<\/code><br \/>\n  <em>Widely considered the most accurate formula for repetitions under 10.<\/em><\/li>\n<li><strong>Epley Formula (1985):<\/strong><br \/>\n  <code>1RM = Weight &times; (1 + (Repetitions \/ 30))<\/code><br \/>\n  <em>Favored in powerlifting and American football strength conditioning.<\/em><\/li>\n<li><strong>Lander Formula (1985):<\/strong><br \/>\n  <code>1RM = (100 &times; Weight) &divide; (101.3 - (2.67123 &times; Repetitions))<\/code><\/li>\n<\/ul>\n<h2>1RM Working Percentage Matrix for Hypertrophy vs Strength<\/h2>\n<table style=\"width:100%;border-collapse:collapse;margin:25px 0;text-align:left;\">\n<thead>\n<tr style=\"background:#059669;color:#ffffff;\">\n<th style=\"padding:12px 14px;border:1px solid #047857;\">% of 1RM<\/th>\n<th style=\"padding:12px 14px;border:1px solid #047857;\">Repetition Range<\/th>\n<th style=\"padding:12px 14px;border:1px solid #047857;\">Primary Neuromuscular Adaptation<\/th>\n<th style=\"padding:12px 14px;border:1px solid #047857;\">Rest Interval Between Sets<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#f9fafb;\">\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\"><strong>90% \u2013 100%<\/strong><\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">1 \u2013 3 reps<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">Maximal Neural Drive &#038; Motor Unit Recruitment<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">3 to 5 minutes<\/td>\n<\/tr>\n<tr>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\"><strong>80% \u2013 89%<\/strong><\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">4 \u2013 7 reps<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">Pure Strength &#038; Myofibrillar Hypertrophy<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">2 to 3.5 minutes<\/td>\n<\/tr>\n<tr style=\"background:#f9fafb;\">\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\"><strong>70% \u2013 79%<\/strong><\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">8 \u2013 12 reps<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">Sarcoplasmic &#038; Myofibrillar Muscle Hypertrophy<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">90 to 120 seconds<\/td>\n<\/tr>\n<tr>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\"><strong>60% \u2013 69%<\/strong><\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">13 \u2013 20 reps<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">Muscular Endurance &#038; Metabolic Stress (Lactate)<\/td>\n<td style=\"padding:10px 14px;border:1px solid #e5e7eb;\">45 to 60 seconds<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Protocol for Accurate Submaximal 1RM Testing<\/h2>\n<ol>\n<li><strong>Warm-Up Thoroughly:<\/strong> Complete progressive warm-up sets (e.g., 50% &times; 8, 70% &times; 5, 80% &times; 3).<\/li>\n<li><strong>Choose a Load for 3 to 6 Reps:<\/strong> Select a working weight that allows at least 3 clean repetitions but no more than 6 to 8 repetitions before technical failure.<\/li>\n<li><strong>Stop at Form Breakdown:<\/strong> Count only repetitions completed with full range of motion without structural cheating.<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>Calculate your One-Rep Max (1RM) safely using Brzycki and Epley equations. Master training percentages for power (90%+), hypertrophy (70-80%), and endurance without injury.<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_kr_title_hi":"","_kr_excerpt_hi":"","_kr_content_hi":"","_kr_takeaways_hi":"","footnotes":"","_kriyasya_companion_story_id":0,"_kriyasya_story_eligible":false,"_kriyasya_story_exclusion_reason":"","_kriyasya_world_key":"fitness","_kriyasya_world_bridge_enabled":false,"_kriyasya_audio_in_world":false},"categories":[80],"tags":[],"kriyasya_format":[],"kriyasya_editorial_origin":[],"kriyasya_content_kind":[],"kriyasya_devotional_focus":[],"kriyasya_tradition":[],"kriyasya_language":[],"kriyasya_observance":[],"kriyasya_healing_modality":[],"class_list":["post-31079","post","type-post","status-publish","format-standard","hentry","category-tools"],"_links":{"self":[{"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/posts\/31079","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/comments?post=31079"}],"version-history":[{"count":0,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/posts\/31079\/revisions"}],"wp:attachment":[{"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/media?parent=31079"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/categories?post=31079"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/tags?post=31079"},{"taxonomy":"kriyasya_format","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_format?post=31079"},{"taxonomy":"kriyasya_editorial_origin","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_editorial_origin?post=31079"},{"taxonomy":"kriyasya_content_kind","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_content_kind?post=31079"},{"taxonomy":"kriyasya_devotional_focus","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_devotional_focus?post=31079"},{"taxonomy":"kriyasya_tradition","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_tradition?post=31079"},{"taxonomy":"kriyasya_language","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_language?post=31079"},{"taxonomy":"kriyasya_observance","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_observance?post=31079"},{"taxonomy":"kriyasya_healing_modality","embeddable":true,"href":"https:\/\/kriyasya.com\/pulse\/wp-json\/wp\/v2\/kriyasya_healing_modality?post=31079"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}