About this tool
Glycemic load (GL) tells you how a real-world serving affects blood sugar, combining glycemic index (a quality score) with the actual grams of carbs in the serving (the quantity). It is a more practical measure than GI alone.
How it works
GL_meal = sum of GL across all foods
Per meal: under 10 low, 11 to 19 medium, 20+ high
Per day: under 100 low, 100 to 120 medium, 120+ high
Glucose has GI 100 by reference. Most fruits and legumes are below 50. White bread, white rice, and many breakfast cereals are 70 or higher.
The EMI / mortgage formula
Equated Monthly Installment is fixed monthly payment that pays off principal + interest over the term. The formula:
EMI = P x r x (1+r)^n / ((1+r)^n - 1)
where P = principal, r = monthly interest rate (annual / 12), n = total months. Every payment is the same amount, but the SPLIT between interest and principal shifts over time:
- Early payments: mostly interest. On a 30-year loan at 7%, the first payment is ~85% interest, ~15% principal.
- Mid-loan: roughly 50/50 around year 18-22.
- Late payments: mostly principal. The last year is ~5% interest, ~95% principal.
Interest cost vs rate (30-year, $300K principal)
Going from a 3% rate to a 7% rate more than doubles total interest over the life of the loan. A 1 percentage point increase on a 30-year mortgage adds ~13-15% to total payments.
Fixed vs adjustable rate
| Type | Description | Best when |
|---|---|---|
| 30-year fixed (US) | Same rate + payment for 30 years | You'll stay in the home 7+ years; rates are low; you want predictability |
| 15-year fixed (US) | Same rate, paid off twice as fast | You can afford 50% higher monthly payment; want to save 60-70% on interest |
| ARM / variable | Rate adjusts every 1-10 years to a benchmark + margin | You'll sell within the fixed period; current ARM rate is significantly lower than 30-fixed |
| Tracker (UK) | Rate = Bank of England base + margin | You expect base rate to fall; comfortable with payment uncertainty |
| Variable Canada | 5-year discounted variable | You can absorb 100-200 bp upside; want lowest opening rate |
How to actually reduce total interest
- Bigger down payment: each $10K extra down saves ~$15-20K over 30 years at 7%.
- Shorter term: 15-year mortgage payment is ~40% higher than 30-year, but total interest is 60-70% lower.
- Biweekly payments: 26 half-payments per year = 13 full monthly payments. Knocks 4-6 years off a 30-year loan automatically.
- Extra principal: even one extra payment a year saves 6+ years of payments at the end. Apply to principal, not next month's payment.
- Refinance when rates drop: rule of thumb - refinance when you can drop ~75 bp AND will stay long enough to recoup closing costs (~24 months break-even).
- Recast vs refinance: lump-sum recast re-amortizes without changing the rate or term. Lower closing costs than refinance; rate stays the same.
The PMI / LMI / insurance gotcha
Many loans require mortgage insurance when the down payment is below 20% (US PMI), 20% (Canada CMHC, mandatory below 20%), 20% (Australia LMI). This is insurance for the LENDER paid by the BORROWER. It typically costs 0.5%-1.5% of the loan annually and adds nothing to your equity. Strategies to avoid:
- Put 20%+ down (US: removes PMI; Canada: still required but premium is lower)
- Piggyback loan (US): a second mortgage of 10% so the first stays at 80% LTV
- Lender-paid PMI: higher interest rate but no monthly fee
- Request PMI cancellation once your LTV is below 80% (US legal right since 1999)
Frequently asked questions
What is glycemic load vs glycemic index?
GI ranks foods 0 to 100 by how fast 50 g of their carbs raises blood sugar. GL adjusts that ranking by the actual carbs eaten, so it reflects real-world impact. Watermelon has high GI but low GL because a slice has few carbs.
What are healthy GL targets?
Per meal, aim for a GL under 10 to keep blood sugar steady. A daily total under 100 is considered low, 100 to 120 medium, and above 120 high. Most weight-loss and diabetes-control plans target under 100 per day.
Why do I care about GL?
Lower GL eating reduces insulin spikes, hunger swings, and risk of type 2 diabetes and cardiovascular disease. It supports steadier energy and is the basis for low-GI Mediterranean and DASH-style diets.
How do I lower a meal GL?
Swap white rice or bread for legumes, oats, or whole grains. Add protein, healthy fat, vinegar, or fiber to the meal as these slow gastric emptying and blunt the glucose response.
Why does the bank show a different EMI than this calculator?
Banks often include processing fees, mortgage insurance, property tax escrow, or homeowner's insurance in the quoted 'monthly payment'. The calculator shows pure principal + interest only. Add ~$200-400/month for the escrow + insurance components in US/Canada/AU.
Should I make a 20% down payment or invest the extra?
Compare: 20% down avoids PMI (~1% loan/year) and reduces principal you pay interest on. Investing the same amount might earn 7% historical equity returns long-term. If your mortgage rate is below 5%, investing usually wins. Above 7%, the down payment wins.
How is interest calculated - daily, monthly, yearly?
Mortgages compound monthly in most countries (US, UK, India). Canada compounds SEMI-annually (a quirk of Canadian law). The displayed rate is annual; the formula uses rate/12 except in Canada where it's slightly different.
Can I pay off a mortgage early without penalty?
In the US: usually yes - most conventional 30-year fixed mortgages have no prepayment penalty. In Canada and UK: there's often a 3-month-interest or interest-rate-differential penalty on fixed-rate loans. Check your specific loan agreement.
What's the difference between APR and interest rate?
Interest rate is the cost of borrowing. APR (Annual Percentage Rate) includes the rate PLUS fees (origination, points, mortgage insurance), expressed as an equivalent annual cost. APR is the better comparison number when shopping lenders. APR is always equal to or higher than the rate.
How accurate is the Glycemic Load Calculator?
It applies the standard formula. Accuracy is limited only by your input precision. For decisions with material consequences (taxes, medical, legal, structural), use the result as a starting point and verify with a qualified professional in the relevant field.
Is the Glycemic Load Calculator free to use?
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads around the tool but not inside the calculation flow.
Are my inputs saved anywhere?
No. All inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but the analytics never see what you type into the form.
Can I use the Glycemic Load Calculator on my phone?
Yes. The tool is responsive and tested on iOS Safari, Android Chrome, and major desktop browsers. Touch targets meet Apple's 44pt and Google's 48dp minimum.
Does the Glycemic Load Calculator work offline?
Yes. Once the page has loaded, it works without internet. The calculation runs in JavaScript on your device.
How do I report a bug or suggest improvement to the Glycemic Load Calculator?
Email hi@3tej.com with the URL of this page and a description of what you saw vs expected. We typically respond within 72 hours.
Can I share results from the Glycemic Load Calculator?
Take a screenshot or copy the output. The page doesn't generate shareable URLs for specific calculations - inputs stay in your browser only.
Why are the results different from another glycemic load tool?
Most likely: different formula assumptions, different default values, different rounding rules, or different applicable rates. Check the methodology if both tools document it. Both can be valid for different scenarios.