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10th October 2025
12:39pm BST
Mathematician Bobby Seagull used data from a sample of 1,000 18 to 30 year olds who were in a long-distance relationship whilst at University and calculated key factors based on what they think the secret to a successful long-distance love is.
He's taken into account how many miles they spend travelling to see each other (m), how many texts are exchanged (t), the number of calls (c) as well as the amount of time they confess their love (l).
(v x mₙ) + (t x c) + (l x r)
d + s
The weighted formula reflects the effort put in by a couple (top line numerator of the equation) against the challenges (bottom line denominator of the equation).
And the higher your Long-Distance Love index, the more likely your relationship will succeed.
Sarah Rosier, Customer Experience Director for National Express, which commissioned the formula, said: "This autumn has seen high school sweethearts parting ways and going to separate universities.
“So, we wanted to find the perfect formula to help them stay together.
“Maintaining a long-distance relationship isn’t easy, particularly when you’re also studying and living that lifestyle as well.”
The formula comes after research of 1,000 adults aged 18-30 who are or were in a long-distance relationship while studying found they typically only saw their partners three times per month.
And they had to travel an average of 171.3 miles to do so.
As a result, every month costs these couples almost £170 in travel costs, moving between destinations to catch up with their loved one.
But 85 per cent reckon they would have seen – or would see their long-distance love more if there were more affordable travel options.
The majority of these journeys were completed by train (72 per cent), although 30 per cent would drive and 27 per cent would catch a succession of local buses.
Sarah added: “Our research shows that it’s clear that the cost of a long-distance relationship can cause friction.
“Constant train travel can really add up, which is why hopping on a coach between cities is often far more affordable.
“With hundreds of frequent coaches serving destinations across the UK, it means students have one less thing to worry about and can make the most of their budget while spending precious time with their long-distance loves.”
Every day, the typical respondent sent their other half a whopping 68 messages and would speak with them on the phone four times.
And they’d end up skipping four and a half days’ worth of lectures or classes because they were away visiting their long-distance love.
But the research, carried out via OnePoll, found 72 per cent said their long-distance relationship has worked out and they’re still together.
According to those involved in long-distance relationships at university, the secrets of success when it comes to love, were deemed to be calls every day (69 per cent), a constant stream of texts (61 per cent) – and the knowledge that the separation isn’t permanent (62 per cent).
While top tips to staying happy included keeping positivity levels up (53 per cent), supporting each other’s ambitions (47 per cent) and sharing daily updates (44 per cent).
Bobby Seagull added: “It was great working with National Express to put together this formula to help long-distance loves stay together while they are at university.
“If they stick to the numbers there is a high chance they can make this work.”
LONG-DISTANCE LOVE INDEX =
(v x mₙ) + (t x c) + (l x r)
d + s
v = visits per month (2.84)
mₙ = normalised miles travelled (actual ÷ “too far” threshold): 171 ÷ 256 ≈ 0.67
t = daily messages (68)
c = daily calls (4.08)
l = daily “I love you”s (7.54)
r = resilience factor (e.g. proportion who agree long-distance makes them appreciate time together: 86% = 0.86)
d = distance difficulty (cost & travel barrier proxy e.g. monthly spend £168 ÷ £277 threshold ≈ 0.61)
s = stress factor (proportion who found it expensive & said it nearly broke them up: 0.68 × 0.44 ≈ 0.30)
Using data from the survey
LDL = (2.84 x 0.67) + (68 x 4.08) + (7.54 X 0.86)
0.61 + 0.30
= 285.83
0.91
= 314 (rounded figure)
If your relationship scores over 300 on the Long-Distance Love index, your chances of success are high (72 per cent of students say their long-distance relationship did work out)
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